Reviews of 9 electronic gold testers
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LEFT Analyzer £379.00. RIGHT Pro £595.00
CONTENTS
This article reviews several electronic gold testers, including how they compare with using chemical (acid) testers.
SUMMARY
COMPARISONS CHART
Auracle ANALYZER £379.00
Auracle PRO £595.00
DISCONTINUED MODELS
ELECTRONIC TESTERS OR ACIDS?
RELATED ARTICLES
SUMMARY
The Auracle ANALYZER has the same electronics (microchip) as the KEE tester, giving an almost instant result, just like the KEE, but on an LED scale rather than an analogue meter. And there's a digital display telling you what to do, a nice touch.
Auracle PRO is fully digital, one-touch calibration and it's CE-approved and much more stable than any of the old AGT models.
The KEE was discontinued in November 2025, it had an analogue meter and was very simple - and very reliable. It is included in the Comparisons chart, below, because it was so well-known and highly-recommended that you might want to know how the latest models compare.
COMPARISONS CHART
|
|
Testing range |
Display |
power |
LowBatt indicator |
Cal** |
Probe life (max) |
CE Approved |
|
Auracle Analyzer |
8ct – 24ct |
LED (carat) LCD (prompts) |
Battery Mains |
Yes (“low batt”) |
18ct |
6000 tests |
Yes |
|
Auracle Pro |
8ct – 24ct |
LCD (various modes) |
Battery Mains |
Yes (percentage) |
18ct |
6000 tests |
Yes |
|
KEE* |
8ct – 24ct |
Analogue meter |
Battery |
No |
18ct |
3000 tests |
No |
* Now discontinued.
** To keep these testers working accurately you need to calibrate them against known samples.
Auracle ANALYZER £379.00
This has the same electronics (microchip) as the KEE tester - that's a good recommendation (see review of KEE tester, below). Instead of an analogue meter, the ANALYZER it has a row of LED lights, so you can see how close to any standard carat (9ct, 14ct, 18ct, 22ct) the item is. This is a greatly improved version of the old AGT1 Deluxe (the manufacturers say, "20% more accurate) - and in addition to the LED display is an LCD display that gives instructions.
PROS
- TWO displays, one for the reading and one for instructions
- One-touch calibration, no need to turn a knob
- Only requires one calibration sample, not two.
- Low-battery indicator (and easy to change the battery)
- The pen-probe has finer tip than the Kee (easier to test very small items) and lasts longer and costs less.
- Slightly smaller and lighter than the KEE, carrying pouch included.
CONS
- Old-fashioned in appearance, with the LED lights, not super-slick like the latest model (the PRO, scroll down).
- More sensitive than the Kee, the item has to be well-filed before testing.
- Each time you start testing you must prime the pen-probe (the manufacturers incorrectly use the word 'charge') by carrying out two or three 'dummy' tests.
CONCLUSION
I'd recommend this new model (Analyzer) over the KEE (same electronics so same reliability) - best value, a no-frills tester that simply tells you the carat of the gold.
Auracle PRO £595.00
The latest tester, with the most features, the one PROs (professionals) go for.
It has two modes.
Standard Mode shows you the results to the nearest commonly-used carat in jewellery, with a 'graph' showing if it's slightly more or slightly less than expected.
Enhanced Mode also shows you the purity (gold content) in percentage e.g. 79% if it's .790 (so, in this example, you can see it's slightly higher than the expected .750 for 18ct). If you don't understand that, then we suggest you get the ANALYSER model instead, it's simpler!
PROS
- Instructions and results on one large LCD display
- One-touch calibration, no need to turn a knob
- Only requires one calibration sample, not two
- Battery indicator show percentage (and easy to change the battery)
- The pen-probe has a finer tip than the older (e.g. Kee) pen-probes, easier to test small items, and the pen-probe lasts longer and costs less.
CONS
- It's American, the "standard" carats (though they say K for 'Karat') start at 8ct not 9ct, and the tester will show you 8ct, 10ct, 14ct, 18ct or 22ct. So if you want to test very specifically for 9ct, you will have to use it on Enhanced Mode.
- More sensitive than the Kee, the item has to be well-filed before testing.
- Each time you start testing you must prime the pen-probe (the manufacturers incorrectly use the word 'charge') by carrying out two or three 'dummy' tests.
CONCLUSION
If you are a professional jeweller you will understand "Carat" and will know that (when using it on standard mode) a reading is at the high end of 8ct or low end of 10ct - then it must be 9ct; you will also understand (when using it on enhanced mode) "percentage" and "parts per thousand" and how they convert to the standard carats used in jewellery. TIP: if you don't understand this, please keep it simple, buy the Analyzer instead!
Also, as a professional jeweller who buys gold, you should be spending several thousand pounds per day on jewellery and scrap, this tester should pay for itself in a day or two, it's the latest and the most sophisticated, so what's the point in going for a lesser model?
DISCONTINUED MODELS
THE KEE was the most reliable, simplest, tester of all time, with its analog meter and low-tech. calibration by turning an actual physical knob. We sold this from 2018 until the manufacturers discontinued production in November 2025.
The same electronics (in particular the microchip that gets it to work so well) was transferred to the Auracle ANALYZER.
PROS, simple design, fast response, the needle on the meter would shoot up to the carat marked on the dial in a couple of seconds; accurate when testing high carats (needed very careful calibration with both and 18ct and a 22ct sample); extra set of leads for testing large items that won't fit on the test plate (though we' heard of anyone to needed to use them!).
CONS, no option for a mains power supply, it's battery-only, and no battery level indicator; not reliable for testing platinum, the best you can say of a "platinum" reading is, 'It might be platinum or Palladium"; for testing high-carat gold accurately you have to use two calibration samples and calibrate it very carefully, not 'difficult' but quite fiddly; Very fiddly to change the battery.
Although the following haven't been made for a few years now (and, therefor, the following information is for 'interest-sake only') we do still sell replacement pen-probes. Replacement pen-probes are usually available for a few years after a model has been discontinued.
The AGT1, AGT2 and AGT3 are all Auracle models. The M24 is by Mizar.
Not all AGT1s are the same!
AGT1 (original model)
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 many people try for a few minutes 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 2 or 3 times, then you must 'charge' the probe by carrying out a few 'dummy' tests before getting a reliable reading, and all of this takes a couple of minutes. Every few days 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 very accurate at testing above 18ct.
AGT1 Plus
Compared with the AGT1 (original) above, 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.
AGT1 Deluxe
The full name given by the manufacturer's is AGT1 PLUS DELUXE
The supplier says that the electronics were re-designed and you don't have to 'charge' the probe before use...but they also say that you should charge the probe anyway. We couldn't find any difference between this and the earlier models as regards operation.
Superseded, in 2025, by the Auracle ANALYZER, scroll up for a review or click here to buy. They manufacturer says the ANALYZER is "20% more accurate". The don't say 20% more accurate than what. We assume they mean 20% more accurate than the AGT1 Deluxe.
NOTE: the AGT1s were discontinued a few years ago. There are plenty on the market, second hand, but please don't send any to us for repair, they are not repairable.
AGT2
A pen-probe, a testing plate, a box of electronics (not shown in the manufacturers pictures) and the connecting leads. You connected it to your phone. It was discontinued in 2018. Then they discontinued the app. so that updates on your phone (or if you got a new phone) stopped it working.
AGT3
Fully digital version, new sleek design, one-touch calibration, superseded, in 2025, by a much-upgraded version (same design but better electronics), the Auracle PRO
MIZAR M24
ACCURACY. 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. OK if you want to know if an item is "low carat" or, possibly, "high carat" - otherwise, fairly useless. PROS. very cheap; - very simple, a light for each carat; Mizar make a few models, this is by far the best of them. CONS. not accurate.; the acid contact fluid will dissolve the sensor if it is not cleaned meticulously after every use; 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 tiny items; no carrying case, no mains power option, no way of calibrating it. CONCLUSION. We did once sell this, because there are always customers who must have "the cheapest" - but, in the end, we decided there were just too many complaints.
ELECTRONIC TESTERS OR ACIDS?
Before deciding on an electronic tester, it's worth considering acids. We speak of, "the acid test' meaning the absolute proof. Safety. The electronic testers we sell do not use acid so they must, by definition, be 'safer'. However, acids are only hazardous if you are 'exposed' to them. 'Exposed' means getting acid on your skin or inside your body. Wear acid-proof gloves (very cheap, we sell them) and don't sniff or drink the acid, then there is no exposure, no risk, no hazard. Accuracy. If you want to test high-carat accurately (e.g. to see the difference between 21ct, 22ct and 23ct) acids are more accurate. Electronic testers do not accurate when testing white gold or platinum. Flexibility. Acids can test for silver, white gold, platinum, Palladium and steel. Ease-of-use. Electronic testers are easier but even acids are 'easy to use' once you've tested your first dozen items and have got the hang of it. Consumables. Acid has a shelf life of about a year, but pen-probes (which are filled with a salt solution) also have a shelf life of about a year. In both cases, if you do a lot of testing you will use up the fluid in less than a year. A bottle of acid costs about £15.00, a pen-probe about £45.00. An analogy: a pen-probe is like an all-in-one ink cartridge, bottles of acid are like individual ink cartridges. Reliability. Modern testers are reliable but any electronic device can break down. If it breaks down within the one-year guarantee period, we replace it; once out of guarantee it is not repairable. A bottle of acid can't break down, you use up the acid, you buy a new bottle. More. See Guide to Chemical Testers.
There are several other methods of testing precious metals, see Twelve methods of testing gold, silver and platinum.