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 pen-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, you will need a sample of 18ct to calibrate (match up the electronics with "carat") it - available as an optional extra if you don't already have an item of hallmarked 18ct. Using an 18ct sample for calibration gives the most accurate results on 9ct to about 20ct. 

The KEE is also good for testing high-carat gold: with careful calibration using both an 18ct and 22ct sample you will be able to test 20ct to 24ct accurately. 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. 

Every electronic tester, including XRF* testers (£12,000.00 to £50,000.00) only tests the surface – the KEE is no exception: you must file the surface with a fine needle-file (supplied) to remove any plating. You do this in a place where it won't show. If you are not prepared to do this, you cannot test jewellery, you cannot buy scrap, you cannot test anything**.
* Some XRF testers can test through very thin plating.
** The only method that is totally non-destructive method is specific gravity


  • 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 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 "up to a few thousand tests" according to the manufacturer. A survey of our customers shows that with regular use in a shop a pen-probe will last anywhere from 3 to 18 months (the longest reported time was 2 years and the shortest 6 weeks). A probe is guaranteed for one month from the date of purchase.


  • as with all electronic gold testers the item must be filed, to remove any surface plating - see "DETAILS"
  • 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)
  • fine needle-file 
  • carrying pouch
  • 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. You could use a 14ct sample instead of 18ct but 18ct is better.
  • If you want to test over 18ct (about 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 you will need the calibration samples. 


Pen-probes have a limited guaranteed! - a pen-probe is like a felt pen, if you don't replace the cap firmly it dries out. The manufacturers say it will give "up to a few thousand tests" (which could mean any number less than 1000). They also say it should be replaced after a year (a year from the date on our sticker).

Although our survey (see  comments from customers  below) indicates that they last between 3 and 18 months, we know that some customers are still using them after 2 years, and we know that some customers need a new probe after 6 weeks. Pen-probes are guaranteed for one month from the date of purchase (invoice date) irrespective of how often it has been used.

Comments from customers: 

  • The KEE 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. 
  • Sometimes a probe lasts a few months but sometimes only a few weeks.

Shelf life v. Guarantee: 

  • Although the manufacturers recommend you change the pen-probe after a year, if it's still working, it's fine. Providing you are still able to calibrated the tester, you will get accurate results.
  • We put a date (month/year) on each pen-probe. This is the date WE took delivery, it is to show when the pen-probe is getting to be a year old, it does not affect the guarantee which is a month from the date YOU purchased it.  


  • 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)