Written by Kiriakos A. Triantafillou, Industrial maintenance electrician, Hellas.
This GW Instek GDS-320 is the first portable Oscilloscope and multimeter which arrived to ITTSB Blog for a product review.
My invitation so to receive one sample was send to GW Instek "the powers that be", few weeks before the opening of Taitronics 2014 (Taipei International Electronics Show), and I am very glad that I did receive their positive answer.
Since May 2012 ITTSB Blog started by contributing to it readers written product reviews by focusing and exploring product details who has major importance to professional electricians’.
And this specific product review will also follow this path too.
At 16 March 2013, ITTSB Blog managed to get it very first and extremely advanced desktop oscilloscope that is a GDS-2102A.
Most significant criteria about choosing it is the fast signal processing speed and naturally it high 80,000 per second waveforms update rate, which makes possible for the user to have an real-time visual presentation of the on going action of waveforms and mostly of pulses.
By using my bench top GDS-2102A for two years now, mainly for electrical measurements’ after adding also in my arsenal several necessary optional probes for voltage and current measurements’, today I have collect a significant pack of personal experiences which some of them I will share with my readers in this product review.
Questions which will be also answered by this review are:
a) How fast waveform update is truly needed for electrical applications’?
b) Isolated inputs as default option and limitations
c) Selection criteria for portable oscilloscopes as: Robustness, weight, easy to use, waterproof, pricing tactics, modern applications requirements’.
I am researching the market of test and measurement equipment for four years up to date, and especially as a blogger I am constantly a News seeker.
My opinion is that definably the portable oscilloscope market is one huge disappointment regarding fresh R&D which it would remove the bottleneck of portable oscilloscopes regarding their waveform update rate.
The forbidden publicly announced specification from all brands so far is the waveform
update rate of their portable offerings.
While in bench-top Oscilloscopes’ the waveform update rate is known and some times becomes a key selling point, this does not happen to portable ones.
The specification which first ITTSB reveals in public view is that up to date, no matter the pricing point of such products their waveform update rate is down to 100 times per second.
What we do usually see in the screen of portable Oscilloscopes of today and especially in electrical measurements even at 50-60Hz, is a poor visual waveforms representation.
Other known issues:
a) Reviewed signal seems to change in slow motion even when amplitude change is rapid.
And this is happening due the poor waveform update rate of the oscilloscope.
b) At such low frequencies’ all Oscilloscopes drop down their sampling rate by default to a much lower than their max of 1Gsa/s, while this behavior is considered as normal, this causing an additionally degraded image quality over the oscilloscope screen.
This is not that noticeable at bench top Oscilloscopes’ due their higher resolution screens, but at a 3” screen which is limited to 640 x 480 resolution or lower, the image quality becomes even lesser attractive at the naked eye.
c) Lack of fast waveform update rate is also translated to large dead time in signal acquisition which practically is explained as slow re-arming of the triggering from one acquisition until the next.
And in simple English such an oscilloscope is totally blind to capture glitches and abnormal signals.
In out times in which power transformation is now made by pulses, this change forced all ready many multimeter manufacturers to update their multimeter speed and accuracy, so their products to become far more compatible to latest applications.
The addition of a low-pass filter for harmonics suppression is one of the indications that this DMM it is designed by having in mind latest needs about modern electrical motors troubleshooting.
Another indication of high performance is a faster sampling rate too, which this similes in the world of oscilloscopes’ to equipment capable for more acquisitions in the unit of time.
By focusing again to oscilloscopes performance I will say that this specific product review, it did helped me to realize many things and among them is the fact that waveform update rate specification is variable not only according to time division setting, but also according to the type of the signal under review.
And now I am finally aware that an oscilloscope has a greater difficulty measuring and displaying signals of pulses instead of electronically generated waveforms by a function generator.
If you have not skip to read this review chapter No 2? Then now you are almost aware of what this part of my review will be about.
The practical workaround about assisting an oscilloscope so to have a lesser dead time when it does it capturing is to select to record the signal at it internal memory, and to review all captured data as to be pictures of your family photo album, by the hope to discover a captured recording which includes abnormal signals.
Some well build oscilloscopes they do include additional tools so to assist in such a memory search, by offering search option parameters, and in this case the oscilloscope trying just by it self to match the requested search criteria by examining the recorded data.
But what happens if you do not know of what you are looking for? The best that you can do is to try several triggering parameters by the hope that your search will return back with some useable results.
The offering of modern and fast oscilloscopes with high waveform update rate is that they do minimize the instances which the user will have to record on memory, and he can trust more his oscilloscope about reviewing abnormal signals at real time mode.
Oscilloscopes testing and performance verification is not easy to do with out having special test circuits which can reproduce pulses and abnormal signals.
GW Instek when released GDS-2102A that is capable for 80,000 wfms/s, the company it did add to it two additional and special test signals.
Those test signals were placed there for demonstration purposes and also as proof that their latest offering it has true potentials at capturing and displaying abnormal waveforms up to the range of 100 KHz, and the second signal is about to demonstrate a fast waveform sweep which works as proof again about real time graphical representation.
GW Instek test signals description:
1) FM modulation ranging from 100 kHz to 1 MHz (waveform sweep at fast interval).
2) Pulse Signal at 100 kHz which including a pulse train and a non repeatable at specific interval glitch pulse.
Today ITTSB Blog is equipped with regular function generator and also with a more modern arbitrary function generator, plus the test signals of GDS-2000A series.
And I do think that all those test equipment as signal sources are more than enough for a basic evaluation of portable Oscilloscopes.
At this benchmarking other than GDS-320 and GDS-2102A I did added an one old basic DSO the RIGOL DS1102E which has a hypothetical (undocumented) 2000 - 2500 waveforms update rate, this it did failed even at 100 kHz pulse test signal.
RIGOL DS1102E is a 100MHz 1Gsa/s oscilloscope.
My testing shown that GDS-320 has equal performance with GDS-2102A in most tests, and GDS-320 shown as a bit sort only at 100 kHz to 1 MHz (waveform sweep) test signal.
The visual symptom was that while the oscilloscope was displaying the waveform sweep at real time, the waveform seemed unattractive possibly due the lesser acquisition points.
Lesser acquisition points is normal behavior when an oscilloscope measuring at a higher bandwidth.
The higher you get, less acquisition points are made over time by the oscilloscope and this has impact even at the graphical representation of the waveform.
Because the target group of this review is mainly fellow electricians, the plan is to keep it as simple as possible.
All that I will say is that what matters the most is a modern oscilloscope, is to be able to retain it highest acquisition point’s and fast waveform update in the range in which they are the most of our everyday applications regarding waveforms and pulses.
This RIGOL DS1102E represents here as a sample of DSO of the past, it is usable when the expectations are limited to a basic numeric measurement in which highest accuracy is not that important, and it is also usable for an graphical representation of known type of waveforms, which actually translating at the needs of a student when starts exploring waveforms and toying around by using a signal generator for a first time.
What my testing shown is that this old RIGOL oscilloscope is not capable to handle correctly the specific pulse-glitch detection test, even at just 100 KHz.
The true advantage of modern oscilloscopes is their raised capability for proper pulse glitch detection.
And this is where DS1102E failed, but what brings true sadness is the thought that all previously released portable oscilloscopes are having only the 1/20 of the power that this basic oscilloscope has.
In the real world all professionals’ troubleshooters’ are getting paid so to solve problems, and therefore they are in need for tools which does not hide similar significant limitations.
My own Oscilloscopes benchmark offered to me the reinsurance that GDS-300 series is as fast enough so to be used for demanding electrical applications involving pulse glitch detection.
Such applications’ could be pulsing power supply repairs, and additionally for troubleshooting at variable frequency drives and even for all sort of troubleshooting relative to inverters.
GDS-2000A series with 80,000 waveform update rate is definably an Oscilloscope of another higher class, much faster one which has further usability in the world of electronics applications which requiring a much higher bandwidth regarding pulsing power supply repairs.
70% of such applications are always handled over the workbench and GDS-2000A series is well prepared as it has a large screen and a well designed control panel which both of them work in favor of ergonomics.
About pulsing power supply repairs I will say that if demands are much higher than what GDS-2000A can do, nowadays GW Instek has available and another new offering, this is GDS-2000E which comes with a Waveform Update Rate of 120,000 wfm/s and it is capable to handle this pulse glitch test at the frequency of 1 MHz.
GDS-320 performance testing, loaded me with much of enthusiasm and pride.
Now I am aware that 30,000 waveforms per second translating to total satisfaction for demanding electrical measurements’.
The rest of my review will focus over actual product details which are many, but my plan is to mention the far more important to me.
GDS-200 has 1M record length per channel, 5,000 counts as DMM and does not support temperature measurement.
GDS-300 has 5M record length per channel, 50,000 counts as DMM and also supports temperature measurement.
At temperature measurement there are choices of supported thermocouple and available options are B, E, J, K, N, R, S, T, (Regular multimeter comes by default at supporting only a K-type thermocouple).
Both series sharing the same 800 x 480 (screen resolution) and a 7” TFT screen among with the capacitive touch pad, and exterior design, and naturally the 30.000/s waveform update rate.
By receiving GDS-320 for a product review I did feel allot of joy and excitement but at the same time and a bit nervous.
The addition of the capacitive touch screen become for me the bigger question mark regarding the time needed for me so to adapt to it.
By personal choice I do avoid to own and use newest large screen smart phones, mostly because the sense of mobility and robustness is not their strong point, especially when used in to unfriendly working environment.
An electrician working in the industry some times simile to an acrobat or athlete, climbing and getting is narrow spaces is part of the job.
Therefore I am a regular GSM phone user, and this translates that I have a small experience about using a touch screen.
By starting using GDS-320, the first lesson for you is to adjust and synchronise your own fingers movement according to response time of the capacitive touch screen.
A long screen tap can activate another function and a too short screen tap will not activate anything.
Complete synchronisation is the key about using this touch screen and you worst advisor here is your own rush about getting the job done.
Gesture control is nice at scaling a waveform over the screen, or about setting the trigger point manually.
But definably is not that easy so to set it as your need to, with out using your own hands as to be and another precise instrument.
And even if you do so, there is no warranty that you will succeed by the first time.
Additionally I am in denial to remove the clear screen protector that GDS-200/300 gets shipped with by default, even by be aware that with out it, the touch screen it would probably become further responsive, especially at Gesture control.
I would consider GDS-320 as friendlier if it was also equipped with a wheel type control knob, capable to collaborate with the touch screen at waveform scaling or about setting a trigger point.
Solely use of touch screen simile to me as a motorcyclist who did buy his first car.
Eventually he will adjust about using both with identical skill, but not right away.
Strongest point of GDS-320 is how successfully the auto-set working even at complex signals.
This fact makes GDS-320 to start looking as single button device, which does all the work by it self, and user interaction will not needed most of the times.
For electrical measurements’ GDS-320 it does offer an additional advantage because is able to display up to four measuring parameters simultaneously.
This Measure window at lower right corner, does the hosting of those four measurements and this further extends to DMM window.
• Simultaneous DMM and DSO operation
• Portrait and landscape modes
• Large 800 x 480 TFT panel and capacitive touch panel
• 7.4V/6100mAH battery for up to 4 hours operation
• Support for differential probes
• Handy APP's - EE calculator, chip resistance calculator, attenuation calculator
• Shielded BNC terminals
• DSO Features
• X-Y mode
• Go/No Go
• 36 automatic measurement functions
• Trend plot
• Edge, Alt, Video and Pulse trigger functions
• FFT, FFT rms, +, -, /, * math functions
• Replay function
• DMM Features
• 50,000 counts
• DCV, DCA, ACV, ACA, R, Diode, Continuity, Temperature
• Fuse protection for the current ports Interface
• Mini-B USB device port
Definably this is a great of pack of features which are escorted by a friendly graphical user interface too.
Most frequently needed settings are definably easy to navigate to them, but the probe Attenuation Ratio it is somewhat hidden.
The Oscilloscope screen is large enough and usable at in-door and even out-door but not by been directly facing the sun.
Most known limitations of every product having such a color screen applying here too, and definably this is not necessarily a bad thing.
GDS-320 despite it dimensions it does deliver the visual quality which my bench top GDS-2102A delivering too.
Among the two oscilloscopes naturally my vote goes to GDS-2102A, this has larger screen font size and this detail gives the advantage of using it and reviewing the measurements’ from a larger distance.
But let’s not forget that GDS-320 is a handheld meter and as such, the working distance from your eyes it can not be longer than 60 centimetres.
At that working distance from it, the experience of using the oscilloscope is truly fantastic.
Waveform details and measurements’, and even the user interface, everything is easily viewed and at high clarity.
In the positive side of things there is no washed up colors, everything seems natural if you have previously experiences with a bench top oscilloscope.
Definably few small differences are present, among them for example the placement of default frequencies counter which is now at the top left corner.
What seems and is important is that GDS-200/300 is over all very user friendly, people who feared that an Oscilloscope despite it usefulness’ is a rather complicate to handle equipment, they will definably reconsider their opinion as soon they start working with those Oscilloscopes.
GDS-200/300 definably has similarities’ with a tablet PC, by a pull down menu the user has in front of him a software based tool box separated by two main windows, the first is about oscilloscope settings menu and the second is the APP menu.
Not all users have identical requirements about software tools, but what GW Instek did is to offer more tools tailored according the needs of engineers who dealing with advanced calculations.
But even so the Advanced DMM APP is the one which every one will enjoy by working with it.
About screen settings, personally I did find satisfactory for most times the brightness level set at 70% and ECO mode (energy saving mode) active at 50% of brightness level decrease after 5 min of inactivity.
I do recommend this setting as default about to conserve battery power, but feel free to adjust it according to your own likes or needs.
All user preferences regarding settings are preserved when power off and power on GDS-320 for your next working session.
And this is great because you do not need to reconfigure GDS-320 when working with optional active probes for High voltage or current measurements’.
GDS-320 does simultaneous DSO and DMM operation and it DMM window is always visible at the right lower corner of the screen.
DMM specific User settings are not retained over a power off/on cycle, and DMM defaults at DC volts.
Extensive details of DMM mode will be mentioned at the next chapter of this review.
Exterior design of GDS-320 is well made, there are strips of molded rubber over it corners and a long one stripe is molded over it left long side.
The long rubber stripe similes to a multimeter rubber case which offer good grip for single hand operation by supposing that you hold the instrument vertically by your left hand.
Naturally all these rubber molded stripes translating to very minimum protective armour against impact in case of an accident.
Definably GDS-320 in not drop proof, and neither is specified as water resistant or water proof.
While GW Instek it does offer with these products a soft protective case and a soft carrying case, what I plan to do in the future would be to buy a hard case of some quality, so to move around GDS-320 safely even in unfriendly work environments’ in which carbon deposits and dirt is all over the place.
Personally I am not that worrying about GDS-200/300 robustness that much, I am aware that this tool is designed to serve demanding electronics troubleshooting and also in electrical demanding applications by succeeding in both.
My only choice prior the release of GDS-320 would be carrying instead an armoured DSO brick of poor performance, and this is something which I was trying to avoid all this years.
Internal electronics of GDS-200/300 getting cooled by active cooling, internal fan rpm is controlled by DSO it self and is totally noiseless.
Demonstration of such details are available in the video which I did about GDS-320, therefore feel free to visit the link at the bottom of this page.
And finally regarding exterior design of GDS-200/300 it worth to be mentioned that GW Instek added to them something unusual and this is a camera tripod mount at the bottom of it (under the banana plugs).
This is to serve mainly about to attach the offered wrist strap which comes as default option, and this is to serve as all times additional protection from a catastrophic free fall due slippery hands or other reason.
Definably this camera tripod mount is compatible with regular camera tripods, but definably I wish to discourage any one thinking to use it over a camera tripod.
Oscilloscope probes and test leads cables will act as death trap to such setup, and therefore this idea is not recommended.
GDS-320 product packing list:
GDS-320: 200MHz – 2 channels Oscilloscope
Probes: GTP-2000A-4 (10:1 / 1:1)
Test Leads: GTL-207
GAP-001: Wall type AC to DC adaptor
GSC-010: soft carry bag
GSC-011: soft protect bag
GWS-001: Wrist strap
User manual on CD, and a printed quick guide
Definably GDS-320 product packing list seems generous and it is, regarding offered quantity.
A close examination will shown that Oscilloscope probes and multimeter test leads, are somewhat lesser exotic when compared with ultimate quality ones.
Oscilloscope probes tips do not seem exchangeable.
Color marking rings for channel identification can hardly stay in place.
Alligator ground clip is tiny compared to it rubber boot, and this makes them unusable.
I did replace both alligator ground clip by better ones and this detail made both probe fully workable again.
Multimeter test leads seems just good but not best, they come with extremely sharp tips which definably electricians will enjoy, they are of hard metal and pinching isolation sleeve of wires is easy to do.
But at electronics components measurements’ did not shown as great.
Especially at resistance measurements in which GDS-320 shown to need about four seconds of 100% perfect test leads contact with device under test, so to display a stable measurement (Firmware V1.08).
AC powered battery charger is made of high quality electronics, never feel warm.
Robustness over time is unquestionable, but there is a downside regarding DC volts power quality, operation at Oscilloscope mode with the charger connected to it is not recommended when your application is about measuring low volt signals.
There is a slight noise pollution which increasing active channel floor noise.
What I would expect to see in the near future as GW Instek option, is a power bank for GDS-200/300 which will offer extended battery life up to 12 hours.
And even a USB cable 2m long to come as standard option.
Regarding storage solutions the carrying bag seems robust and definably is of good quality and seems splats proof too.
The carrying bag has plenty storage compartments for carrying all default option accessories and even GDP-040D differential probe.
But as mentioned and above as personal preference, this would be a much larger hard case, which other than further protection for the Oscilloscope it would offer additional storage capacity for carrying with me additional test leads and my Chauvin Arnoux PAC12 AC-DC active probe for current measurements.
GDS-200/300 by default does simultaneous DMM and DSO operation, DMM is always active in a window at the lower right corner.
By the first look what are visible are the digits of 50,000 counts, a single touch over them will activate a new window with buttons relative to measurement mode selection.
I can not use the word range switch here as we do in analog multimeter, because neither this description fits well anymore even today, all latest digital multimeter do auto-range by default.
Either way in this new window you may select your preference about a DMM function, and the next step is to connect your test leads at the proper front banana jacks.
GW Instek added over GDS-200/300 a dedicated APP with the name Advanced DMM and this is a very wise choice, the supposed Basic DMM window is tiny regarding dimension of digits and about control buttons.
Advanced DMM APP is definably an eye candy, has nice large digits, functions selector seems a bit compressed is size, but still there is no complain here.
High priorities of easy to read and easy to use, both are served well by this APP.
Advanced DMM APP Voltage measurements’
Definably GDS-320 is a speed demon in ACV and DCV measurements.
Range: 50mV, 500mV, 5V, 50V, 500V, ± (0.05% + 5 digits)
And at 1000V ± (0.1% + 5 digits)
That is a total of 6 ranges.
While measurements’ per second specification is not listed at product documentation, ITTSB tests verified that faster display update rate is equal to 7 times per second.
This is extremely fast and identical to capabilities of Agilent U1273A industrial handheld DMM at 30,000 counts.
Accuracy comparison was performed by using BRYMEN BM869 that is another high quality meter at 50,000 counts native display resolution.
Both meters measured identical up to the last count.
A negligible difference was spotted at 1-2v DCV at two last digits, and at higher volt their measurements’ was as looking in to a mirror.
Advanced DMM APP – Trend plot
I could not enjoy the benefits of this function especially at monitoring or logging 220 ACV.
The problem is the highest range that gets automatically selected and is at 500V.
ACV disturbances’ of ± 5-10 volts can hardly show in the Trend plot.
And this translates that measurements’ of 110V ACV mains will not benefit either from this graphical representation.
Min-Max is more useful and you may use it among with Trend plot, by using pause function, so to get information of exact ACV value at a time, and even time duration information of the occurred event.
Unfortunately this Advanced DMM APP is missing of few important features’, there is no manual range setting, no Auto-Hold setting, and no option to save recorded Trend plot data in the form of a screenshot (Firmware V1.08), which this it is possible at GDS-320 Oscilloscope interface.
Trend plot function due it size and pixels resolution, definably has more to offer regarding visual detail at the range of 50V and lower.
Advanced DMM APP resistor measurements’
I got very displeased by measuring resistor values, not regarding measurement accuracy but due the behaviour of the meter it self.
Possibly this could be a first firmware glitch detected which will improved later on.
The symptom is that tests leads should be in perfect contact with DUT for four seconds at least so the measurement to stabilize and be displayed.
Additionally it is required total concentration from the user and a bit of force about holding firmly / steadily, both tests leads tip over the DUT for those four seconds.
I am unable to say if Auto-range is slowing down the fast response of the meter, but as long an alternative manual range selection is missing, you have stuck with this questionable performance (Firmware V1.08).
Advanced DMM APP Diode & Beeper
Diode mode works beautifully and very fast as in every high class fast meter.
Beeper mode seemed not that fast as it requires test leads to be in contact for 1+1/2 of seconds (by estimation), so the meter to respond by an audible sound.
Beeper has no volume control, but seems more audible compared to regular handheld DMM, because GDS-320 has ventilation holes at the back and therefore the sound travels freely for inside to outside.
Advanced DMM APP mV AC-DC
Tested this range by using a new comer AC/DC clamp sensor of DER EE Electrical instrument and the measurement were very fast and accurate.
What I did was to use the current limiter of my PSU to 2A DC and use the clamp sensor to measure current.
What missing so this mV range to gain more value to electricians is a Scale function which will convert incoming mV in to an Ampere reading.
I have suggested that to GW Instek by the hope that they will add another new APP dedicated for AC/DC clamp sensor with banana plugs.
Advanced DMM APP temperature measurements’
I got very displeased here again by possibly detecting the second severe firmware glitch and possibly and few programming errors (Firmware V1.08).
While the application seems to work, the temperature reading does not match with real one, possibly due an issue which has to do with the probe type compensation adjustment.
It seems that K type thermocouple has wrong programmed parameter and this causes an error of 10C when is in use.
More software issues were discovered when selecting several other probe compensation settings, and some times those changes caused the APP to crash and GDS-320 stayed frozen, by turning it off and on, it was becoming functional again (Firmware V1.08).
Temperature probe compensation selection is by default set to K type thermocouple, any alteration of this parameter will not keep at next power up sequence.
Using the temperature measurement is a definably a positive experience like no other.
Trend plot adding extreme value to GDS-320 compared to a regular DMM which is limited to just displaying numbers.
Measurement update rate is very fast, Min-Max logging does miracles, and again by pause button you may explore by touching Trend plot and it special cursor, all recorded/logged values.
As soon GW Instek software engineers correct these issues, the temperature measurement feature at GDS-320 will become a true valuable asset.
GDS-320 Battery life – benchmarks
ITTSB conducted several charge-discharge benchmarks so to verify actual performance especially when GDS-320 is in use at multimeter mode, but lets see first the offered specifications’ and a strange Battery Caution note.
Battery Power Li-polymer 6100mA/hr, 7.4V (Built-in) (45W)
Charge Time 2.0 hour (75%)
Operation Time 4.1 hours, depending on the operating conditions
GW Instek Battery Caution Note:
Type: Rechargeable Li-ion polymer Model: FT8862103P
The internal battery should not be replaced by the end-user.
Please return the unit back to your local dealer for assistance.
According to ITTSB benchmarks definably battery life can come close to 4+1/2 Hours when DMM APP is used with ECO mode active which works at 50% display brightness.
Alternatively even with out using ECO mode, and by setting 50% display brightness you may also expect the same battery life at the temperature of 15 Celsius.
Another ITTSB finding is a software glitch which has to do with these battery level warning messages which are shown at the screen in the form of pop-up warning note (Firmware V1.08).
The first warning note it gets triggered when battery is at 20% remaining capacity, and the second when battery is at 10% remaining capacity.
Unfortunately both warning messages not seem correct according to true remaining battery capacity, especially when after the 10% remaining capacity warning note, the GDS-320 kept going for another 2 hours.
Generally speaking the total battery life of GDS-320, or better said the Sum of hours that this equipment will work by a single battery recharge is relative to display brightness but also related to environmental temperature.
Active cooling inside with auto-regulated RPM fan it is also require a portion of battery energy, and this parameter is not controlled by the user.
Therefore it is understandable that GW Instek can not calculate and neither me either, any exact power consumption statistics.
But what they should do it to correct the battery indicator so to display correctly remaining battery capacity (Firmware V1.08), and even to explain further of why? They consider End User as incapable to replace the battery inside of GDS-200/300 series.
And to offer their explanation by mentioning all details in a separate PDF document (Battery Replace Notes), which it would be available at specific product series web page.
The marriage of GDS-320 with GDP-040D probe definably seems as very successful even by a naked eye.
People with experiences at using differential probe will have much less to worry about for example the remaining battery charge level of a 9V alkaline which is the portable power source of a single channel HV differential probe.
GDP-040D is powered up exclusively by main battery of GDS-320!
GDP-040D has shown as well designed product solution in many ways.
The way that is attached over GDS-320 body is smart and this concept works in favor of productivity.
The user now stays in focus about reviewing just the measurement, than keeping an eye over all cable connections of a separate portable HV differential probe, or about finding a safe places for it so this to been kept close to his oscilloscope.
Another true advantage of GDP-040D is that this is actually two deferential probes in to a single box and this is an extremely significant detail, when some one will do pricing comparisons.
GDS-320 among with a GDP-040D is a new product solution which seems as alternative one when compared to portable oscilloscopes with isolated BNC inputs, but it is definably a much better one for my taste.
All HV differential probes in the market work under the same principals’, High Volts are lowered by resistor dividers to a lower voltage, and this gets measured by an electronics circuitry made or precision parts, their final output comes out isolated to ground and in the range of mV.
Their second advantage is their high bandwidth which makes them useful to Oscilloscopes about reviewing waveforms and pulses.
But none of such probes can be perfect when talking about noise-jitter caused by their own electronics circuitry.
Generally speaking all Oscilloscopes with BNC input isolation is always bounded with some degree of noise-jitter, while most vendors talking about an almost transparent circuitry which does the isolation, what they usually hide under the carpet is the actual noise-jitter value.
GDP-040D when compared at ITTSB Blog by an other high quality differential probe shown 20% less noise-jitter, but both probe shown as noise-jitter free at measurements starting from 5V and above.
A good example so my description to be fully understood is the simile of a theatre loaded with people who slightly whispering to its other, this causing background noise which is unavoidable, all actors should keep their voice level always higher than that, no matter what.
AC Voltage measurements seems and are far more accurate when such a probe is measuring several volt up to hundred of volts.
GDS-320 by using GDP-040D as option, this is a better concept.
When isolation is not a necessity the GDS-320 alone has again the advantage of having far more noise-free input channels, in comparison with a portable oscilloscope which has permanent isolated inputs.
This also translates that GDS-320 is capable to enter in both worlds of applications including low noise electronics and even to the world of electrical power measurements, by standing in them as high performance product solution which the End-user does not have to accept any compromises due the offered versatile options.
Most common electrical application to use GDS-320 + GDP-040D is naturally Inverters output monitoring under load.
The testing of this portable oscilloscope it was a major personal challenge for me, in the past five years I have no memory of some one else who spent such a long time with one product, so to offer a comprehensive opinion in writing about it.
Even so this review never intended to be a substitute of information’s available in GDS-320 User manual which has 188 pages.
My very own wish list is rather sort, and this can be explained by the fact that GW Instek did a good research, prior sending GDS-200 & 300 series product design in to mass production.
GDS-320 externally is not tailored to fit in electric industrial applications which coexist in a working environment full of dirt, dust and grease.
But my recommendation or suggestion for a hard case as new storage solution, definably will add to it some body armour and the ability to be used outdoor too.
GDS-320 is primarily the first most powerful portable Oscilloscope for applications related to pulses, inverters, variable frequency drives, and most of pulsing power supply which use pulsing frequency of 200 KHz and below.
And it true advantage is the high waveform update range among with it fast internal electronics, which makes it capable to review glitches and problems which are at the first stage of development.
Other slow performing oscilloscopes up to date can not capture anything before the problem truly escalates in to a magnitude of a large problem or permanent damage.
GDS-320 as multimeter definably has speed and comes with this beautifully looking Advanced DMM APP, and 50,000 counts.
I did liked allot the way that this APP is designed, starting from the choice of the colors and even the size of it digits, which are easy to read even from a large distance.
The addition of Trend plot definably adds value to this APP but as mentioned all ready it usability is maxed at 50V or 50 Celsius regarding measuring range.
Trend plot dimensions are small and there is limits related to pixels size versus recorded graph detail.
While all detected software glitches by my review (Firmware V1.08), eventually will get patched by GW Instek software developers, what is truly missing is the choice for manual range selection other than auto-range, and the function of auto-hold, among with the ability of trend plot to run at full screen.
Definably Advanced DMM APP seems incomplete by not offering the ability to the user to save a screen shot of it.
Currently this is only possible by using OpenWave-200 PC software.
Additionally it would be nice to see and another new software APP to be added to GDS-320 about serving current probe measurements’ of active current clamp probes with banana jack connectivity option, and even to be capable about scaling and displaying mV probe output in the form of Ampere.
A 10mV/ 1A conversion by using a regular multimeter it does seems to me as unproductive, especially today with so much technology around us which it can be used so to serve even is such simple automated conversions.
GDS-320 when gets connected with a windows PC there is not much of benefits, other than the file transfer of saved files.
Additionally by using OpenWave-200 PC software, you may transfer an Oscilloscope measurement at the computer screen with a ability to zoom in the captured waveform, and it second feature is the ability of taking and saving at your PC hardcopy screenshots', from Oscilloscope or DMM mode.
It does makes me wonder of why GW Instek did not thought to create an APP which will use the GDS-320 date time stamp so to serve as DMM data logging recorder.
In the Oscilloscope section they did implement a waveform recorder capable to can record maximum 30,000 automatic and background implementation waveform, and it can continuously record for 7,999 hours if under 1k memory mode and 10s/div.
My sort description will be here that this new portable oscilloscope series is the proof of quality precision engineering in marriage with the necessary quantity of waveform update rate than an electrician will ever need.
GW Instek received the gold award of excellence for this product series at Taitronics fair (October 2014) in Taiwan, and definably GDS-200/300 series product release date has been also recorded among the significant milestones of test and measurement equipment history.
GDS-200/300 series are definably loaded with significant innovation.
These products is the New which eventually will push away the old, and portable Oscilloscopes’ market will never look the same in the years to come.
And I do feel lucky about becoming one of the first ones which started seeing things with fresh eyes.
All troubleshooters and even engineers we do have the same problems regarding our field work applications, our needs are frequently changing when newer machinery taking the place of the old.
In order to keep up with these changes, is our obligation to stay flexible even at adopting new tools and fresh troubleshooting methods.
This GDS-320 product review made me realize for another one time, that GW Instek is passionate and energetic Oscilloscopes developer.
I got very pleased that GDS-320 is able to deliver high quality visual representation of waveforms on screen, and that it over all performance it is similar my larger GDS-2102A bench top Oscilloscope, regarding the bandwidth of electrical applications.
The combination of GDS-320 with GDP-040D dual channel differential probe has tremendous value for an electrician and when that equipment gets combined with a hard carrying case the outcome will be an undisputable winner.
While over the years GW Instek has a good record as bench top multimeter developer, at specific GDS-200/300 series, at Advanced DMM APP it is obvious that software developers did not demonstrated yet the necessary passion for perfection (First release Firmware 1.08).
Fresh released Firmware 1.09 (April 2015) it does include improvements’ and even adding previously missed functionality at Advanced DMM APP.
1) Hardcopy (screen shot) function is now added at DMM APP
2) Continuity function has faster audible response
3) Ohms measurement has improved, now the measurement is available in about 2.5 seconds of time.
4) At Temperature measurements’, temperature menu has now a new option which you need to set manually the ambient temperature first.
Ambient temperature can be entered by using a special key pad menu.
Some how this change seems to me as a better approach, about correcting up front any calibration difference of a K type thermocouple.
In order for me to set correctly GDS-320 to work accurately with my Agilent K-type thermocouple I had to connect the thermocouple first at my BRYMEN BM869 multimeter, and to set the needed compensation at GDS-320 menu so it measurement to be identical with BM869 DMM.
5) Advanced DMM APP stability has further improved, but definably will need a further touch up.
6) Battery status indicator and remaining battery charge messages have been also corrected, and my latest test with the new firmware shown a battery life of five hours.
Possibly the next Firmware 1.10 it would heal an issue at Min/Max, I did detect a bug that Min value at trend plot (measuring temperature) does not update by an even lower min value, but just by it self every 10 seconds or so, and this causing Min/Max over time to be identical.
It does feel good seeing most software glitches’ to be healed at GDS-200/300 series by the first firmware release.
When I got my GDS-2102 it firmware fine-tuning took several months, but now is definably a mature product, and the same I expect to happen over time for those portable gems too.
Regarding the battery replacement at GDS-200/300 series, GW Instek made known at their product page (frequently asked questions) that the battery is soldered over the main board, and this is why it recommends an authorized service center so to replace it.
According to my own knowledge Li-Po cells has a life span of 400 recharge times or an average of three years.
As consumer it would be nice to be aware up front of total price of such repair cost, but by assuming that this will keep in the range of 100 EUR or 100 USD, that scenario does not seems as overkill to me.
My answer in the question: if GDS-200/300 series is able to act also as bench top oscilloscope replacement?
Personally I have not been convinced yet that this is an option at least for me.
Over my workbench the representative of GDS-2000A series, does truly a great job, and even after two years of ownership it does continue to be my most favorite tool attached to a 220V mains plug.
Therefore I am ready to accept that GDS-200/300 series are definably oscilloscopes born to travel, and also that their high performance bonded with mobility will be their stronger selling point for a long time ahead.
GDS-200 series pricing seems somewhat friendly compared to other competitors offerings, but is not cheap either.
Due the fact that GDP-040D probe keeps busy both oscilloscope inputs, combined volt and current measurements is possible only by using a current clamp probe connected exclusively with banana jacks, and I truly hope or wish to see an special made APP for such current sensor probes in the future.
I have also the faith that the addition of a new DMM data logging APP dedicated for volts and current measurements’, by making good use of date and time stamp, it would offer further more value to the end user.
Saving logged data to .CSV is an option that is currently missing.
In 2015 with such advanced technology around us, the true merchandize is now software related smart ideas able to push forward our productivity, and I do feel the need to congratulate GW Instek for their new product series.
But with out adding in the arsenal of GDS-200/300 series of another two or three APP which I am suggesting here, customers related with electrical engineering and troubleshooting will have more second thoughts about making a buying decision.
My prediction will be that in the months to come, offerings of portable Oscilloscopes’ which are extremely oversized and heavy, and the supposed economy version comes with black and white screen, and with CCFL backlight which aging and contrast loss are known over time issues, they will fade away as product design concept.
This GW Instek GDS-300 product promotion video among with these secret agents it did seemed to me rather as over enthusiastic concept in the beginning, but now I will agree too with the hidden message behind this video which is that GW Instek has now in their hands a powerful handheld equipment which it can handle much more applications which previously, this was only possible by moving around bench top equipment.
I wish to thanks GOOD WILL INSTRUMENT CO. LTD. for their cooperation and their decision about sending this Sexy and Beyond carrying case among with gifts to Greece, for a close examination of their latest product development by an Industrial electrician.
I will always carrying it around with pride!
Pictures gallery , GDS-320 temperature measurements tests, YouTube GDS-320 Video.
Note: Use picture gallery button + to scroll images
Note: Use picture gallery button arrow for auto play = Recommended method
Note: Use picture gallery button arrow for auto play = Recommended method
Note: Use picture gallery button +, to scroll images
Pulse glitch Test / All contesters :-)
Pulse glitch Test GDS-320
Pulse glitch Test GDS-2102
GDS-320 / Advanced Multimeter APP (screen shots of modes) V, mV, mA , Ohm,
Note: Use picture gallery button +, to scroll images
GDS-320 / Advanced Multimeter APP - refrigerator thermostat testing
YouTube GDS-320 Video
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