2) The challenge
For several years ITTSB Blog this is a source of content relative to product reviews of handheld multimeter.
Testing of highest Ohms measuring range this always was a challenge mostly because high resistance elements (large resistors) they are unpopular merchandize especially in small stores them serving Greek market of electronic components.
My own workaround at 2013 this was about me to buy eleven large resistors of ¼ Watt.
Then I use a project box among with a single rotating switch of nine positions this serving as selector.
By combining two or more resistors I managed to have a working resistors box with eight steps regarding Mega Ohm values, lowest this is 1M and highest this is 29.5M.
Back then, selection of any specific product specifications’ as for example their actual resistance value or about their working voltage among with measuring tolerance (%) this was a luxury which I did not have.
Even so I was very happy about what I did accomplished, mostly because I did succeed at making a simple verification box this having sum of resistance value that no true application will ever use in electronics, but still usable for my purpose which was testing (benchmark) of multimeter, and testing results was for my eyes only.
Unfortunately and as far I am aware of, most popular application for a multimeter this measuring high resistance this was HV transformers’ serving in televisions with tube technology, in recent years this application has vanish from most parts of our planet.
Insulation testers they are products especially designed to serve at measuring electrical insulation, and this is application with no expiration date.
Collapsed insulation at any electrical system this translates to death, or injure of people (if they are lucky), or in to tremendous damages in equipments and materials down to their total destruction point.
And first conclusion this is that all Insulation testers they are meters of tremendous value speaking of importance.
Measurements’ made by Insulation testers they do translate in to verification that everything is good, or as warning message about a critical upcoming event.
In recent years, over all product performance and build quality of Insulation testers, this is defined by strict electrical standards.
Compliance to such electrical standards this is mainly responsibility of any brand this making Insulation testers.
Unfortunately not everyone engaged in manufacturing of Insulation testers he can be trusted, low-cost products with out branding they do circulate from Asia to other destinations worldwide every day, most of them by not having any truly confirmed compliance, or a true mailing address of any product manufacturer.
First arrived at ITTSB Blog Insulation tester for a product review, this is BRYMEN BM878 multimeter & insulation resistance meter.
For several months I was looking to discover sources of high resistance elements made for such a special application.
Due Capital Control policy in the Banks of Greece (and for a very long time), I was unable to buy any goods from a foreign country, therefore I faced two serious problems both working against release date of this scheduled review.
Within 2017 they are branded sources worldwide and makers of measuring standards, and they do offer such special solutions.
My very own market research helped me at making several realisations’.
a) Such manufacturers’ they are not that many, and such products they look hidden as they are mostly presented inside of product catalogues.
b) Most to all of such manufacturers’ nowadays they do all use Thick Film resistors in their products.
c) Vishay Foil Resistors brand this is most popular choice about such products solutions (of high resistance elements) and a major provider in this products market segment.
d) Major customers of such products those are calibration labs, and this translates that high prices of calibration standards it’s not a major problem for them, those are tools of their job, they making money from them.
e) Currently only one or two brands made the thought so far, about them to deliver an simple version as verification box with three of four values of high resistance elements.
f) Insulation resistance meters nowadays they sold much cheaply than several decades ago that Megger brand in UK introduced such tools in the market.
g) While pricing of insulation resistance testers this is now much affordable, their electronics are and will be fragile and therefore verification of good operation this is a new obligation for any one using them, or else you cannot trust such testers in long term.
h) Unbranded insulation resistance testers this is not a tool that you can use and expect any reliability.
Personally I am tremendously happy with my new DIY solution of high resistance verification box for insulation testers with up to 4000V Test Voltage.
My plan was to create something with undisputable electrically correctness and this translates to spotless selections of build materials, product design, high quality resistance elements, and finally a true flawless made verification box.
Research time of my project this was tremendously long, as I was forced to study and discover all theory about resistance elements them operating in high voltage.
Today I can proudly say that I did succeed making something very special as verification box, this now giving me the opportunity to say that ITTSB Blog products testing workbench this is today one step further to completeness speaking of measuring standards’.
Testing of any insulation resistance tester this is now possible, and my own product reviews will deliver much higher value to my readers.
Vishay Foil Resistors brand and POWERTRON products acted to me as trigger, so me to dive in and begin knowledge hunting regarding this sector of products.
Nowadays I have the awareness that I got extremely lucky speaking of timing and place and even of planets position, because I got in contact with a resistance elements manufacturer whom using leading technology and this translate in to a market leader regarding such special products.