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 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 - it was the most 'sophisticated' tester on the market but I didn't like it. Not so with the Kee tester! The kee 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. However, the KEE is also good for testing high-carat gold: with VERY careful calibration using both an 18ct and 22ct sample you will be able to see if it’s “Probably somewhere between 18ct and 22ct” or “About 22ct” or “Possibly better than 22ct”. For accuracy (not just giving an impressive-looking reading!) that is better than any other electronic gold tester I have evaluated.

If you are only interested in getting an accurate reading up to 18ct, there is no need to bother calibrating the KEE with a 22ct sample. 


  • tests gold from 8ct to 24ct (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 18ct 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 them)
  • 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 18ct.
  • If you want to test over 18ct (up 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. 


The manufacturer says a probe lasts for " up to a few thousand tests" - which could be anywhere from 100 tests to 5000 tests.

To answer the question we carried out a survey of customers who had been buying probes for two or three years and the conclusion is: a probe lasts between 3 months and 18 months, this being (as an estimate, because nobody counts) between 1000 and 5000 tests. 

Comments from customers: 

  • The KEE probe tests on average about 40 items a day and lasts about 6 months, 5000 tests. The solution in the probe outlasts the tip which becomes soiled from testing scrap. We replace the probe when reliability drifts and more regular calibration is required with our 18ct control sample.

  • We get around 3 months and test around 10 times a day, often 15 times a day. Overall we think they last well. 

  • Our probe only lasted 3 months, we are very disappointed.

  • It's variable, some probes last approximately 12- 18 months each (about 2000 tests) and some  9 - 12 months (about 1000 tests). 

  • The probes seem to last us at least a year, I would say that it was at least 200 individual tests, and perhaps even up to 400 tests over that period. 

However, the probe (pen) is simply a modified felt pen and, like a felt pen, if you don't replace the cap firmly after each use, it dries up. The cap does not 'click' on, you do have to push it firmly. For this reason the probes (pens) are not guaranteed against drying up. 

The manufacturers recommend that the probe is replaced after a year. 


  • Unlike other suppliers, we test each one before dispatch to make sure it is perfect. We do find a percentage that are either a little erratic in their behaviour or which don't work at all - we send these back to the suppliers, we do not sell them to our customers. 
  • of those that we sell (they work fine when we test them) the percentage that develop a fault in the first year is less than 1%, which we consider quite acceptable.


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)