FG-100 Soldering Iron Tip Thermometer - Calibration - Extending it functionality

[Kiriakos GR]

Since the year 2009 and up to 2024, I can safely assume that they were sold a huge number of based at FG-100 electronic design thermometers.

Some people naming them as Hakko clones, but in electronics product design originality this has disappear since 90s.
Many factories working as hidden and they make money as OEM sources and their goods gets constantly rebranded.

FG-100 this is product model originally distributed by Hakko (Technology of 2011), then the brand decided to distribute more high-tech versions of it.
The Chinese factory which did production of FG-100, did not stop producing, and this stock now circulates under several names.
China this is a communist country, there is a big government council, these members they are politicians and factory owners.
There is partial internal control of whom makes what, along pricing control.

By the numbers, poorly working copies of FG-100, they were made by tiny factory these has a very sort life within China mainland.

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Back in time that Hakko this were prime distributor of FG-100,  they did also something smart for them.

FG-100 product design this also support connectivity of regular K-type thermocouple, all that is required is to connect one, over the two active sensor pins.
Hakko introduced a pack of called options, which are two accessories both based at the concept of external K-type thermocouple.

Hakko replacement sensor code= 191-212
There is nothing special to it, because it using dissimilar metal / material, this be standardized since 70s.

At the year 2022 Hakko started to distribute a new form of sensor,  this named as AS5000 thermocouple (calibration inspected version).
And they do advertise extended linearity.   

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Soldering station calibration:
95% of soldering station sold out there they have a huge linearity Error.

You may calibrate for example the station at 200C and the linearity error at 300C will be significant and at 400C the temperature might be 50C lower than of digital display reading.
Because of that fact, soldering professionals using such external thermometers more frequently, so them to come closer to specific electronic component soldering specifications.
Or else, sensitive components will burn, and or electrolytic capacitors might have only 1/3 of specified life cycle.
 
In theory the overpriced soldering stations, they are somewhat better behaving regarding the delivery of linearity Error.
New technology of heating element and soldering tip all-in-one, this seems as improvement regarding soldering repeatability but they are not miracles either.

Since the beginning of time, anything involves the word precision, it is also expensive to get.
 

Regarding regular soldering irons: FG-100 it can simply confirm good thermal transfer of the tip in use.

Regarding soldering station with out display:
The severe issue of linearity Error  this apply to most soldering station, with and with out display.
In simple words,  you will be an idiot if you do demonstrate blind trust at any soldering station display.

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Yesterday I did also decided to pay 12.20 € (shipping + 24% VAT) about buying one RST FG-100 thermometer, with five replacement sensor included.
In my lab I have make one reliable gadget also based at K-type thermocouple for soldering tip measurements.
And therefore one interesting comparison will follow. 


Product design of FG-100 this is inexpensive at massive production line,  and no higher than 2$ USD per unit.
Because of that fact, beware that anything priced over 13$ USD this is stealing. 

[Kiriakos GR]

Proper way to use of FG-100 Soldering Iron Tip Thermometer

Soldering process has it own secrets, they are not many but they are known mostly at production lines.
High temperature soldering this came along with lead-free solder.
And a third new factor this is the use of special type of Flux (special soldering cream that withstand high temperature).


The proper way to measure with FG-100 this is 9~10 second of contact between tip and sensor.
Solder wire must be added, along with regular solder cream or Flux.

The wise to do this is using regular solder cream up to 280C for nine seconds.
And or.
To use high quality Flux for testing at 280 ~ 500 Celsius. 

(The regular solder cream tends to evaporate much faster than special branded Flux).

Now, the most stupid think to do with FG-100, this is to try to measure hot-air rework station by blasting the sensor with hot air 

Maintenance Note: Occasional terminals cleaning due isotropic alcohol (and no other substitute). 

[Kiriakos GR]

FG-100 aesthetics: 

I have very well trained eyes at finding significant information just by looking a photograph.

At endless FG-100 listings you do mostly see stock photos and not the entire truth.
I did catch one detail, in a very few listings there is a white washer at the moving pin over the FG-100.
 
Not all sellers act professionally so to deliver a Teflon washer with the meter,  but some other times its a buyer mistake, as the seller it does store the washer with the pack of sensors, and the unaware noobs they do not know for what this is for? 

One noob at Ali Express, he received two pcs of washer, and he installed then both.   
At another example,  Teflon washer this has it center hole looking as covered, and is buyer responsibility to push and remove the cut piece that the factory forgot to remove.

[Kiriakos GR]

191-212 Sensor / Change-out rate of sensor

The sensor replacement period is about 50 times per single sensor in general, but this changes
depending on the temperature used and the components in the solder and flux.
If you use lead-free solder, the sensor needs to be replaced more frequently.

If the sensor degrades because it is being eaten away by the solder, it will register a low
temperature.
Even if the sensor is not broken, replace it after about 50 measurements.
Even if the soldering tip has degraded, the temperature will register extremely low.
Keep these points in mind and decide on the sensor replacement period.
Caution: The sensor is extremely thin and may break if pushed with force.

191-212 Sensor can only be used to measure temperatures below 500°C / 932°F
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By this last made introduction you are now by 99% familiar about FG-100 whereabouts.
 

[Kiriakos GR]

At the year 2024 I am now glad that the so called as Original HAKKO FG-100, this is now dust of the past.

The clones of the original ( that are anything made at 2016 and older) these had terrible electronics too.
 
Even so, I did spot something funny  , back then one Chinese copycat it did dare to add K-type plug over their production.
He decided to make their thermometer more appealing or useful, by this addition.
Today they are not such products available, but this product design thought it might be considered as smart one.

Hakko Japan, did something more hilarious back in time,  they made several probes that can be attacked over the FG-100 terminals, with a lets called it as shoe - connector.
This shoe - connector has the appearance of  female bullet plug frequently used by automotive industry.

Basically I would not mention neither one of these two of bad product design ideas, if these two did not aim to increase FG-100 usability to also as general purpose thermometer.
But we should not forget, this damn FG-100 stay powered for only three minutes until auto-shut-off this engages.
And as such, it might not be a good idea after all, of us to go DIY so to expand FG-100 connectivity after all.       
       
   

[Kiriakos GR]

FG-100 it might be sold internationally, and or the newer RST FG-100 approximately about 1500 units has be sold too.
Even so I think that language barrier of the buyers is the reason that they did not pay necessary attention at the user manual.

FG-100 by design it does defeat Auto-shut-off (Auto power off), when measured temperature this is above 100C.
And therefore it might worth the trouble and the cost at expanding RST FG-100 connectivity with a quality external K-type thermocouple.     

Here is the link of our mini review.  https://www.ittsb.eu/forum/index.php?topic=1873.0