KEE electronic gold tester (model M-509GM)
KEE electronic gold tester (model M-509GM)
KEE electronic gold tester (model M-509GM)
KEE electronic gold tester (model M-509GM)
KEE electronic gold tester (model M-509GM)
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KEE electronic gold tester (model M-509GM)

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Ref: KEE

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Calibration samples for electronic gold testers

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Pickup available from Quicktest (WD18 8PH)
Email us or call on 01923-220206 for appointment.


Making it with a simple analogue meter seems to have solved the problems found with 'computerised' electronic gold testers. This is definitely the most reliable electronic tester I have seen.

The price does not include a sample of 18ct and 22ct.  If you deal in jewellery you will have these - if not, you will need the 18ct sample for testing general jewellery; plus the 22ct sample if you want to test above 18ct accurately.


  • Size 90 X 170 X 50mm (3.5 X 7 X 2 inches)
  • No acids involved, the probe contains a harmless salt solution.
  • Tests gold from 8ct to 24ct (the scale is marked "K" instead of "ct" because it's American)
  • The pen-probe provides up to 3000 tests.
  • Simple analogue meter, good reliability
  • Simply touch pen probe to the item, result is shown in 2 or 3 seconds, very fast
  • Includes extra contact leads for large items that will not fit on the test-plate.
  • Easy calibration with a sample of 18ct (+ a sample of 22ct gold if you want to test above 18ct accurately) - not included in the price of the tester
  • As with every tester (whether you spend £15.00 or £12,000.00) it only tests the surface. This means you must file the surface with a fine needle-file (supplied with each tester) in a place where it won't show, to remove any surface plating. 



  • Carrying pouch
  • Battery
  • Diamond-impregnated file
  • Very clear illustrated instruction booklet
  • An extra set of leads 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).


To test 9ct to 22ct you will need a sample of 18ct yellow gold (it must be exactly 18ct). This is to 'match' the electronics in the tester to the carat (technical term: calibrate). You cannot use the tester without this.

If you want to test 20ct to 24ct accurately you will also need a sample of exactly 22ct.

You can use anything with a UK hallmark or you can add one (or both) calibration samples to your order, click on View Optional Extras.

UK traders will already have hallmarked items, which is why we don't include the calibration samples in the price of the tester.


The tester is guaranteed for one year.

As of Summer 2022:

  • so far, we've sold a few hundred KEE testers and have had seven returned. Of the seven, one was perfect, two had dry (used-up) pen-probes, one had a flat battery, three were faulty. 
  • we also find that some are faulty when we receive them from the supplier in the USA (unlike other companies, we test every item thoroughly!) - we return these to the supplier, we do not sell them to our customers.


A pen-probe is included with your purchase, if you want a spare, click on View Optional Extras. A pen-probe is guaranteed for one month.

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 this). They also say it should be replaced after a year (a year from the date on its sticker).

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.


  • Generally, a pen-probe lasts between 3 and 18 months but it can be as long as 2 years or as short as 6 weeks - the guaranteed is one month from the date of purchase.
  • Although the manufacturers recommend you change it 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.
  • The date on the sticker on the pen-probe is so that we know which batch it comes from and so that you have an idea when it's getting to be a year old. Irrespective of the date on the sticker, the guarantee is still one month from the date you purchased it. 

      More information

      Click here for more details and a review

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

      Click here see how easy it is to use, download a copy of the instruction manual (.pdf). Compare this with the instructions for other electronic testers!


      Ask a Question
      • Soo Does this Test Just Check the Surface of the Gold? or does it Check the Gold All the way thru?...Like a Gold Bar...Because knowing just the Surface is nothing and not Worth $350 just to know the Surface when it could be Heavy Plated..

        All electronic gold testers (i.e. that tell you the carat) only test the surface;  you must file the surface with a fine file (included) so that you are testing below the surface. There are no exceptions, this applies to the inexpensive electronic gold testers (£450.00) and it also applies to the XRF testers ("cheap" models from £12,000.00, "good" models £40,000.00) and it also applies to acids (about £50.00 per set). 

        If you ONLY deal with gold bars, get an ultrasound detector, this will tell you if the bar is the same all the way through or if there's another metal in the middle. These will not tell you if the bar is gold, it is not a gold tester.  We do not sell these.  Also, they are over £1000.00, so if $350.00* is too much for you...

        * customers outside the UK do not pay VAT (sales tax); this is payable when it arrives in your country. 

      • Hallo, Can you calibrated I want to test 18k 21k 22k

        We calibrate these before dispatch for ALL carats (9ct to 24ct).

        As the fluid in the pen gets used up you will have to keep calibrating it yourself but, to begin with, it's all checked and calibrated and ready to go, you dont' have to do anything, it will work from 9ct to 24ct.

      • Does the Kee test all the way through a gold sample or just part the way through?

        Electronic testers (of any type, any make) do not test all the way though the gold; neither do they test partway through, they just test the surface.  That is why you must file the surface first (a fine needle-file is included with the tester) to remove any gold plating.

      • Can the KEE electronic gold tester be used straight away to test up to 9ct anything higher will need to be calibrated with 18ct - 22ct.?

        It is supplied thoroughly tested and calibrated, it can be used straight away to test any carat.  
        Unlike other brands, you are not required to calibrate it every time you use it. 

        As the fluid in the pen-probe gets used up, the readings become inacurate and then you have to keep calibrating it. 
        Obviously, we recommend getting a calibration sample (either from us, or any scrap hallmarked item) sooner rather than later.
        The calibration sample should be 18ct.  You only need a 22ct sample (in addition to the 18ct sample) if you want to test 20ct to 24ct accurately.

      • Does the tester tell you non gold?

        The short answer is: yes. But it depends on what you mean by "Does the tester tell you non gold".

        The tester tells you how much gold is in the metal alloy (the percentage purity, but measured in "carat" rather than "percentage").
        So if you see that the amount of gold is zero (the red section of the dial)...then the metal does not cointain any gold, it is "non gold".
        So the answer to your question, ""Does the tester tell you non gold" is: yes.

        If, by "Does the tester tell you non gold" you mean: if you can see the metal is not gold will it tell you what the non-gold IS?   
        Then the answer is: no. 

        If, at this point, if you are confused because you don't understand that the metal will be an alloy (in the case of gold jewellery and coins, a mixture of gold and other metals), or you don't understand 'carat', or you don't understand what can legally be described as 'gold' in the UK - then you need The Gold & Silver Buyer's Handbook.

      • Do you supply the replacement probes in the UK and how much do they currently cost?

        Yes we sell the probes, currently (Spring 2022) £49.50.
        Yes we hold stock here in the UK.

      • Do you calibrate this device before despatch?

        Yes, every tester is carefully checked and calibrated before dispatch.