Testers & scales calibrated before despatch

Gem & precious metal testers, since 1986

KEE gold tester: review and detailed information

(model M-509GM)

Click here to buy.

Click here if you already have one, and need a replacement probe.

Click here to download a copy of the instruction manual (pdf)




I am wary of recommending new electronic gold testers, having tried a few that looked promising but turned out to be unreliable. As the leading specialists in gold testing, we evaluate any new tester very thoroughly, carrying out hundreds of tests, before we decide to sell it.

I once sold a make that was fully computerised and really sophisticated, but whenever I was at an exhibition didn't like demonstrating it. I knew it wouldn't always work the first time and that if you repeated a test, you often got different results. Not so with the Kee tester! It works first time, the results are accurate and consistent, I love demonstrating it.  



As with all electronic testers it is most accurate for testing low-carat gold. For high-carat gold (and this is what I particularly like about the KEE) if you very carefully calibrate it with the 18ct calibration sample and the 22ct calibration sample you can get quite accurate results on 20ct to 24ct. Here in the UK 20ct to 24ct is used by the Asian community, and they do want to know if an item is closer to 20ct or closer to 24ct. For general testing of jewellery and scrap from Britain/Europe/USA you really don't need to bother with the accurate testing of 20ct to 24ct.


  • tests gold from 8ct to 22ct (the scale is marked "K" instead of "ct" because it's American)
  • simple analogue meter, good reliability
  • simply touch pen probe to the item, result is shown in 2 or 3 seconds, very fast
  • easy calibration with a sample of 18ct (+ a sample of 22ct gold if you want to test 20ct to 24ct accurately)
  • powered by one AA battery, supplied (will last many months providing you remember to turn it off after use)
  • includes extra contact leads for large items that will not fit on the test-plate (though if you're only testing jewellery, it's unlikely you will find an item that won't fit on the test-plate)
  • the pen probe lasts for 3000 tests according to the manufacturer, though I have not been able to verify this; the best I can say is that given heavy use in a shop it will last 3 to 4 months. (pen probes are not expensive, always keep a spare!)


  • as with all testers (including all other electronic gold testers) the item must be filed, to cut through any gold plating, and to remove any surface contamination
  • it's American, they use the abbreviation "K" for karat rather than our "ct" for carat  no great problem, just worth noting
  • the scale is marked in the American "10K" [10ct] instead of the British 9K (9ct) which gives the impression it won't test 9ct.  It does test 9ct!
  • it does not test silver
  • it does have a "Platinum" reading, but in practice this is of limited use because it can't distinguish platinum from Palladium.



  • an extra set of leads is supplied for testing very large items that will not fit on the test-plate (though I have never known anyone who has needed to use these)
  • Battery (should last many months but, obviously, you must remember to turn it off when not in use).
  • Very clear illustrated instruction booklet by Quicktest


  • you will need a sample of 18ct yellow gold to get the tester to read accurately (technical term: calibrate) on 9ct to 22ct.
  • If you also want to test 20ct to 24ct accurately you will also need a sample of exactly 22ct. UK traders will already have these (any item with a British hallmark) which is why we don't include them in the price.

If you are not a trader or are in a country that does not have government-controlled marks, you will need the calibration samples, otherwise (after a few days or weeks of use) the readings will become inaccurate.


Keep at least one spare probe in stock, they are not expensive and last thousands of tests, otherwise you will find yourself in a busy shop (or on a buying trip) unable to test any gold.

The probe lasts for "up to 3000" tests providing you replace the cap firmly after each test. It s a modified felt pen, it dries up easily if you leave the cap off or don't replace it firmly, and then you will have to buy a new one. For this reason, the probes are not guaranteed. If you buy a replacement probe for future use (i.e. as a spare) we do test it before dispatch, and we recommend that you test it when you receive it.

"3000 tests" should be:

  • 3 to 4 months of use for a specialist gold-buying business, testing gold all day long (we've had this verified by a gold-buyer)
  • 8 or 9 months for a busy jewellery shop with a sideline in buying gold (my guess)
  • about a year for just the occasional testing as a collector-enthusiast (my guess)

The shelf life of the probe should be, "at least a year" (providing the cap is replace firmly after each test). .

As of summer 2021:

  • unlike other suppliers, we test each one before dispatch to make sure it is perfect (out of several dozen we did find 3 or 4 that didn't work at all); so far only two (less than 1%) have been returned faulty - one of which turned out to be a flat battery. 
  • so far, we have not had anyone contact us to ask how to use it or complain about its accuracy, it is definitely the most accurate of all the cheap (under £10,000.00) electronic gold testers I have evaluated.
  • so far, we have not had any complaints about probes not working, but the probe will dry up if you leave the cap off or don't replace it firmly, and then you will have to buy a new one. For this reason, the probes are not guaranteed. 


The KEE tester is by the far the best that I have seen, both for accuracy and reliability.


Click here if you already have a KEE tester and need a replacement probe.

Click here to download a copy of the instruction manual (.pfd)