REVIEWS OF NINE ELECTRONIC GOLD TESTERS


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CONTENTS OF THIS ARTICLE

Summary (all current models): price, ease-of-use, accuracy

Reviews of current models:

- see all

- Mizar M24

- Kee

- GemOro AuRACLE AGT3

- see how they compare

Reviews of obsolete models:

- see all

- GemOro AuRACLE AGT2 for Android

- GemOro AuRACLE AGT2 for Apple

- GemOro AuRACLE AGT BLUE

- GemOro AuRACLE AGT1
We sell the most recent model, there are various obsolete models.

FURTHER READING

See a list of other articles about testing precious metals

 

DOWNLOAD INSTRUCTION MANUALS

AGT3 instruction manual (pdf)
18 pages, beautifully illustrated, badly written, you will need to read it several times

Kee instruction manual (pdf)
7 pages, beautifully written by me, Raffi (photos by Megan)

 

SUMMARY
* Price * Ease-of-use * Accuracy *
Scroll down or click here to see how they compare, in detail

Mizar M24 £159.00 including VAT. Has eight lights: 9ct, 10ct, 12ct, 14ct, 16ct, 20ct, 22ct and 24ct. The accuracy will be plus or minus one light, e.g. if it reads 14ct it might be 12ct or it might be 16ct (but not this accurate above 18ct). It's fiddly to use and it uses a strong acid as a contact fluid which corrodes the machine. You can only test small items. Scroll down or click here to see review.

GemOro AuRACLE AGT1 DELUXE £382.50.00 including VAT. In our Winter 2018 - Spring 2019 catalogue we describe this as "AGT1 PLUS". It is very confusing because they have made several variations of this model, this is the latest of the series which they describe as: AGT1 PLUS DELUXE. It has a row of 32 LED lights between 6ct and about 24ct, so you can judge which carat is lighting up (the reading 'drifts' up an down) - but it is a matter of judgment. My colleague likes this one, he says it's 'very responsive', he says he can 'feel' the carat from the speed of the machine's response. Do not buy this is you have to ask, "Is it easy to use". Do not buy this if it will be used by a succession of shop staff who don't have time to learn. But DO buy this one if you are prepared to persevere until you get the 'knack' - you will end up being able to judge the carat quite accurately: very accurate for 9ct to about 12ct (usually correct to within 1ct); reasonably accurate for 12ct to about 14ct (plus or minus 1ct); somewhat approximate between 14ct and 24ct (plus or minus 2ct). Scroll down or click here to see reviews.

AGT3 £559.00 including VAT. Very accurate at 9ct to about 14ct (usually correct to within 1ct); reasonably accurate at 14ct to 18ct (plus or minus 1ct); somewhat approximate between 18ct and 24ct (plus or minus 2ct). Digital display, sophisticated built-in software. That's good in that you get instructions on the screen, but you must be prepared to suffer the idiosyncrasies of the software with its unexplained errors and crashes. Most of the time these work fine and are reasonably easy to use with clear prompts displayed on the screen. Scroll down or click here. to see review.

KEE. £349.00 including VAT. This is new (as of Summer 2018), I have tested this thoroughly and it's looking good. So far, this wins on being the easiest to use, for consistent reading, and for being reasonably accurate at testing all carats. Scroll down or click here. to see review.

One dealer covers all eventualities: away from customers he uses an electronic tester as a very quick and easy way of sorting the scrap - then uses acid to re-tests high carat (or anything giving inconsistent readings). In front of customers he uses acids because they are more accurate and consistent in their reactions and he doesn't have time to test items twice.

I am always keen to test new electronic gold testers and, as you see, I tell you if it's good, and I certainly tell you if it's bad - so bookmark this page!

If you are happy with the limitations of these electronic testers, as detailed above, you will be pleased. If you want consistent and accurate readings (to the exact carat, guaranteed, every time) up to 24ct you will have to spend upwards of £12,000.00 on an XRF machine...or use acids. If you find an electronic tester (for under £1,000.00) which is claimed to be more accurate than above, please let me know because I've never seen one.

 

REVIEWS


MIZAR M24

Click here to buy, £150.00 including VAT
If you already have one, you may need to buy a refill

PROS

- very cheap
- very simple, a light for each carat
- Mizar make a few models, this is by far the best of them

CONS

- it's not accurate.
- the acid contact fluid will dissolve the sensor if it is not cleaned meticulously after every use, this is not covered by the guarantee
- you need good eyesight and a steady hand to place the test-item into the tiny well that you fill with acid
- you can only test small items
- no carrying case, no mains power option, no way of calibrating it.

CONCLUSION

Use this to see if it's about 9ct or more, then get someone else to test the item properly. Not worth repairing when it breaks down.

Scroll down or click here to see how all the testers compare.

 

KEE
(model M-509GM)

Click here to buy, £329.00 including VAT
(click here if you already have one, and need a replacement probe)

PROS

- good price for a tester that works well
- the easiest to use. You still have to read the instruction manual but apart from calibrating (and cleaning the sample) it's self-explanatory, you won't have to keep referring to the instruction manual to find out about menus and error messages
- fastest response of all the electronic gold testers
- it's more accurate than the other models at testing high-carat (e.g. 20ct to 24ct 'Asian' gold)
- good size for carrying around, in its case with all its accessories it measure 130 X 180 X 60mm (5X7X2 inches)
- extra set of leeds for testing large items

CONS

- not as easy to calibrate as the digital models, you have to turn a tiny knob instead of simply pressing button
- no option for a mains power supply, it's battery-only (though the battery should last many months)

- large items of jewellery won't fit on the test plate, you have to use the extra set of leeds

WHY DOES IT HAVE AN ANALOGE METER AND NOT A DIGITAL DISPLAY?

If you think anything with a digital display must be more accurate than an old-fashioned mechanical meter, please think again. There is no connection between the type of display (digital or analogue) and accuracy. Here in the office we have a digital thermometer that gives a reading to the nearest 0.1 degree. It is not accurate, it gives a 'correct' reading plus or minus 1 degree but it still displays the reading to the nearest 0.1 degree. In our laboratory (where we manufacture chemical gold testers) we have an old-fashioned 'analogue' thermometer, it's accurate to within half a degree. The same applies to gold testers. A digital display will always give you a reading to the nearest 1ct, but it is not necessarily accurate.

CONCLUSION

This is definitely my favourite but it is a new item (as of August 2018). I do like to wait a few months, sell a few, and gauge customers' response, so this article will be updated between now and the new year. I have tested this very thoroughly, I am satisfied it works well!

Scroll down or click here to see how all the testers compare.

Download the instruction manual.

GemOro AuRACLE AGT3

Click here to buy, £559.00 including VAT
(click here if you already have one, and need a replacement probe)


Please see above to find out how the GemOro AuRACLE testers (all models) compare with other gold testers.

PROS

Instead of a row of LED lights it has a digital display. It is not just having a digital display that makes the difference, it's the way they have computerised the on-display instructions. It tells you when to calibrate; when testing, it tells you to wait a few seconds and it tells you when the reading has stabalised and the test is complete; it tells you if the test has failed and you need to try again. All of this removes the element of 'judgment' that you need with the AGT1 models (judging when the row of LED lights have stabalised and you have a valid reading).

Easy calibration, you press one button and follow the instructions, easier than having to turn a knob.

There are two modes of testing. A 'quick' test will indicate the approximate carat (e.g. 10ct [because it's American], 14ct, 18ct or 22ct); a detailed test will give a reading to the nearest 1ct. (i.e. it gives a reading to the nearest 1ct, that does not mean it is accurate to the nearest 1ct).

CONS

The 'prompts' on the screen are very good reminders, so that you don't forget what to do, but you do have to read the instruction manual carefully. The instruction manual is beautifully illustrated but very badly written, you will have to read it several times.

The system sometimes crashes and you have to restart it a few times to get it to work, or the display will only show bands of lines. I have had dozens of email exchanges with Gemoro about this and they insist it's due to "enviromental condtions". I've never got to the bottom of this, if you buy an AGT3 and the display keeps going corrupt, you will just have to keep restarting it until it works, GemOro cannot fix this.

Not accurate for testing above 18ct. For instance, if an item reads "22ct" the best you could say is, "This item is about 22ct but it could be about 20ct or it could be about 24ct". It will still give a reading to the nearest 1ct, but that doesn't mean it's accurate.

Theoretically it tests platinum, but this is not reliable, the reading sometimes indicates platinum and sometimes indicates not gold. And Palladium can read 'platinum'.

Large. Carrying case measures 300 X 150 X 75mm (12 X 10 X 3 inches), not something you can slip into a bag.

Download the instruction manual.

Click here to see how all the testers compare.

HOW THEY COMPARE


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How do they compare for price and for accuracy?

In summary: on low-carat you should get a reading to about the nearest carat (except for the M24, not so good); they are not so accurate on high-carat (except for the Kee, which is better).

How do they compare for size of the machine?

The models that connect to a phone are the smallest, but not quite as small as the photographs suggest, you also have the connecting leads and a matchbox-sized box of electronics. After that, the M24 is the smallest (there is no carrying case), followed by the Kee (in its soft case). The Gemoro (AGT models) which come in huge carrying cases.

How do they compare for the size of items you can test?

The M24 has a tiny 'well' (indentation) which you fill with acid, you must 'dip' the item into this, that limits you to testing small items. The Gemoro (AGT) testers have a good-size test plate which will take all but the largest items of jewellery. The Kee has a smaller test plate (large enough to test most items of jewellery) but comes with a second set of connecting leads for testing items that don't fit onto the test plate.

How do they're compare with XRF?

Also known as "x-ray guns", we don't sell these. But a comparison is useful. XRF testers cost between £12,000.00 and £50,000.00 and display a chemical breakdown of the metal, listing not only the percentage of gold but also the percentage of all the other metals. So XRF is better. In fact, there is simply no comparison. An example: an XRF tester might tell you that the metal contains 44.3% gold, 14.03% silver, 0.6% platinum and 0.05% Palladium. Our testers will tell you it's about 9ct (37.5%), possibly a bit better.

How do they compare for speed of testing?

AGT1 testers are slightly faster to use than acids.

AGT3 and AGT BLUE testers, when set to enhanced mode are about the same speed as acids, though there's not a lot in it, and it depends on the carat. The quick mode is much faster than acids but isn't accurate.

KEE tester is slightly faster than acids.

XRF also has quick and enhanced modes. On enhanced, XRF is slower than both AGTs and acids (the videos always show them in quick mode!)

How do they compare for safety?

AGT and KEE testers use a probe containing a simple salt solution, the M24 tester uses acid.

XRF testers use x-rays, when used properly they present no risk. However, I see them used by dealers who hold items in their hands whilst testing, and so give themselves a dose of radiation several times per day. There is a high chance that this will give them cancer.

Acids must be handled with care. Providing it isn't spilt on skin (simple solution: wear gloves) the level of exposure becomes nil.

How do they compare for consumables?
(The prices include VAT)

An AGT probe costs £29.00 or £35.00 including VAT (depending on which model it is for). The manufacturers say they last up to 5000 tests. Some of our customers complain that they only give 'a few tests', but it's impossible to know how many tests these customers have really carried out or if they are leaving the cap off between tests. One of our customers has four shops and buys three of four probes every few months and is quite happy.

A Kee probe lasts costs £49.50 including VAT. It lasts about 1000 tests, though the manufacturer is reluctant to give a figure, preferring to say that with regular / heavy use in a gold-buying shop it will give 3 to 4 months of use. My own guess is that with light use it will last a year. You must, of course, remember to replace the cap after each use, if you leave it off for just one night, the probe will dry out. The manufacturer recommends that the probe is changed after a year. Until I've sold a few of these, waited a year or two and spoken to lots of users - I can't tell you how long a little-used probe will last.

A replacement bottle of acid for an acid tester lasts for 100 to 150 tests and costs £10.00

A replacement bottle for a Mizar M24 costs £27.50 and lasts about 50 tests.

When an XRF tube wears out, a new one will cost from £2000.00. Plus a service, plus any repairs that are needed, plus VAT...maybe £3000.00.

How do they compare for service and repairs?

If a Gemoro AGT breaks down DURING the guarantee period (one year) it has to go back to the suppliers, Gemoro, in the USA who will 'evaluate' it, then attempt a repair. Only as a last resort will they replace it. OUT of the the guarantee period we can send it back to the USA for a quote for repair, but you would have to pay (in advance) our postage to the USA (£20.00+VAT) plus their postage for its return (£73.50+VAT) with no guarantee that it will be worth repairing. Although Gemoro always quote a couple of weeks for a repair, extensive experience shows that it actually takes 2 to 3 months, and very often it ends up being returned to us marked, "no fault found".

KEE testers are new as of July / August 2018 so I can't comment on after-sales service. For items under guarantee I like to think that (as with our other overseas manufacturers) once we have tested an item and agree it is faulty, they will eventually exchange it, which means we can simply send you a brand new one...and you needn't worry about what we do next. For items out of guarantee: these are made by a small company and the boss is the engineer who designed it, so I am confident he can repair them.

The M24. It's very simple - not worth repairing. We do exchange any that are faulty during the guarantee period (one year) but, after that, there is no point in sending one back. Also be aware that the contact fluid is a strong acid, you must clean the 'well' thoroughly after every test, otherwise the acid dissolves it, and this is not covered by the guarantee.

XRF is likely to cost two or three thousand pounds to repair, we don't sell or service these so I have no experience of their service.

An acid tester cannot 'break down', you simply buy a new bottle of acid.

Which tester is the 'least destructive'?

All electronic testers, from £150.00 to £50,000.00, will only test the surface of an item (though XRF can test through very thin plating, and the latest NITON brands can detect some types of plating) - so you must file the surface first, so that you are testing underneath any plating. The same applies to acids, you must file the surface first. There is no tester that requires 'less' filing or 'more' filing. You must find a discrete place to file, you use a fine needle-file. A file is included with every AGT tester, KEE tester and acid tester.

How do they compare for testing silver, platinum and Palladium?

The AGT, KEE and Mizar testers cannot test for silver - acids can, XRF can.

The AGT and KEE can test for platinum, but Palladium reads as platinum too (and the AGT reading flips between "platinum" and "not gold").

Both acid testers and XRF testers can test for silver, platinum, Palladium and steel.

How do they compare for calibration?

Every gold tester has to calibrated ('checked against' known samples)

If you haven't used a bottle of acid for some time (they get weaker over the weeks and months) you must check it against known samples, any hallmarked gold will suffice.

The AGT testers need to be checked against a 14ct sample and an 18ct sample, you press some buttons, the electronics calibrate the machine to the sample. You will need to do this whenever you turn the machine on, and every few tests, otherwise you will get incorrect readings.

The KEE tester must be calibrated against a sample of 18ct, you test the item whilst turning a knob until it reads exactly 18ct. If you wish to test 20ct to 24ct accurately you must also calibrate it against a 22ct sample.

The M24 tester cannot be calibrated, you just have to hope the readings are more or less correct and don't 'drift' over time.

An XRF tester must be sent back to the supplier if it needs calibrating. I think this costs a few hundred pounds...not sure...not really my subject.

The various incarnations of the
GemOro AuRACLE AGT1

We no longer sell this model, but if you already have one, you can buy a replacement probe from us.

Please see above to find out how the GemOro AuRACLE testers (all models) compare with other gold testers.

See video.

Not all AGT1s are the same.

The original (AGT1) model - obsolete

Quite OK once you've got the 'feel' for how the lights shoot up, then keep going up, then slowly go down, and usually settle on a reading...but not everyone has the patience to spend time 'getting the feel' - many spend a few minutes with it, then give up. Shop staff who don't get proper training and don't have time to 'get the feel' and are under pressure in a busy shop - they will have no chance of getting a meaningful reading. Each time you switch it on you must calibrate against the 14ct calibration sample, sometimes it doesn't work and you have to calibrate it a second (or third) time, then you must 'charge' the probe by carrying out a few 'dummy' tests before getting a reliable reading, and all of this takes 1 or 2 minutes. Every few days (if you're unlucky) or every few weeks (if you're lucky) it has a nervous breakdown and won't work at all, it is not 'broken', you can fix it by calibrating it 6 or 7 times in succession, it's not difficult to do but it is frustrating, especially if you have a queue of customers. Not at all accurate at testing above 18ct.

The (AGT1 Plus) - obsolete

Compared with the AGT1 (original): calibration usually works first time, it has nervous breakdowns less often, it 'feels' nicer to use (more responsive). You still have to 'charge' the probe by carrying out a few 'dummy' tests before getting a reliable reading. It's not as frustrating to use as the original AGT1 but there will still be times when calibration doesn't work the first time and you have to calibrate it 3 or 4 or 5 times in succession. You still need to spend time 'getting the feel' of the readings.

The AGT1 Deluxe - the full name given by the manufacturer's is AGT1 PLUS DELUXE

The suppliers say say that the electronics were re-designed and you don't have to 'charge' the probe before use...but they also say it's a good idea to charge the probe before use. In practice there's nothing to choose as regards operation, but this one tends to be more reliable than the AGT1 Plus..

 

OBSOLETE MODELS

Scroll up or click here to see the models we DO sell

We are THE experts on gold testing and gold testing equipment. Many readers come to this page to see how the various testers compare. Inevitably, some models get to be discontinued. There are many more models which we have tried, found to be useless, have never sold, and I don't include those reviews here. If you have an interesting gold tester that we don't know about, send us a sample and we will review it for you.

GemOro AuRACLE AGT2

Auracle AGT2 electronic gold tester

Discontinued, no longer manufactured

Please see above to find out how the GemOro AuRACLE testers (all models) compare with other gold testers.

The GemOro AuRACLE AGT2 consists of a probe, a testing plate, a small box of electronics (which is not shown in the manufacturers pictures), connecting leads, and a large-ish fitted case. You connect it to a 'mobile device' (smartphone, tablet, netbook etc.) so you already have most of the hardware. There are two models.

GemOro AuRACLE AGT2 FOR ANDROID

PROS

- display can be set to 'digital' (see photo) or 'analogue' (displays a dial with a pointer).

CONS

- you must plug it into a USB port (not all devices have USB ports)
- it's not as small as the picture suggests, there's also a box of electronics
- you must study the instruction book, the instructions are not self-explanatory from the app, many customers don't bother and get into an awful muddle
- you might find, when you get new phone, that the app. no longer works and you will have to wait for the manufacturers to release an update. And at some time in the future the app will no longer be updated and you will not be able to use the machine (this applies to any product that uses an app).

 

GemOro AuRACLE AGT2 FOR APPLE

PROS

- works with any Apple device.
- display can be set to 'digital' (see photo) or 'analogue' (displays a dial with a pointer) - 'analogue' display shows 9ct in addition to 10K ("carat" is UK spelling, "karat" is American spelling)

CONS
- same as the Android version, above, though generally Apple apps are more reliable than Android apps.


WHY WAS IT DISCONTINUED?

- not enough sales. My guess is that customers read about the free app, downloaded it with great excitement, and either didn't realise that they needed to buy a machine too, or expected the it to cost £20.00 - because that's how it goes with 'free apps'. And when they saw that the machine cost hundreds of pounds, they didn't buy it.

 

GemOro AuRACLE AGT BLUE


Click here to buy, £439.00 including VAT


Connects to your phone using blue tooth, so you don't have to connect a wire. The app. is also able to connect to the internet to find the price of gold. Works with Apple iOS; also works with Android mobile devices with Low Energy Blue tooth capability (requires Lollipop version OS or newer).

PROS

- It's the smallest, neatest, fastest electronic gold tester
- Blue tooth and internet connectivity

CONS

- you need to connect it to a phone, it's not a 'stand-alone'
- you might find, when you get new phone, that the app. no longer works and you will have to wait for the manufacturers to release an update.
- at some time in the future the app will no longer be updated and you will not be able to use the machine. This applies to any product that uses an app.
- we cannot support or guarantee the software, if you have a problem you must contact GemOro in the USA

WHY WAS IT DISCONTINUED?
- not enough sales. My guess is that customers read about the free app, downloaded it with great excitement, and either didn't realise that they needed to buy a machine too, or expected the it to cost £20.00 - because that's how it goes with 'free apps'. And when they saw that the machine cost hundreds of pounds, they didn't buy it.

We only ever sold half a dozen of these, not really sold enough to gauge the reliability, but nobody telephoned to ask us how to use it, nobody has complained about its accuracy, this was probably their best model...then they discontinued it.


RELATED ARTICLES

Methods of testing gold (and other precious metals)

More methods of testing gold (and other precious metals)

Acid tests, what he various testing kits do

Testing white metals

Testing gold, specific gravity method

 

 

 

 

 
QUICKTEST, Watford, WD18 8PH, Tel. 01923 220206, email info(at)quicktest.co.uk