Had to learn the correct way to use it. With the numbers on the probe facing you, and the other side against the magnet it reads the proper polarity. Great tool to determine polarity and strength of various magnets and electromagnets.

Nice portable meter to test magnetic fields. Especially useful for me to compare the strength of different electromagnets. I was more interested in relative measurements than absolute, so I have the less accurate model. Not sure what the one reviewer is saying about "cutting the case to get to the batteries". The green protective cover is a flexible material. If you have trouble getting it off, just warm the unit up a bit and it should come off really easy. The screw for the battery cover is NOT captive though, so pay attention when removing so you don't lose it! All-in-all, I'm happy with the purchase.

You have to cut the F—-ing cover off to install the batteries.

Not so very long ago, reasonably priced test equipment was as rare as a free parking space in Brooklyn. But, with the influx of massive amounts of Sino-produced goods via Amazon, an entire array of useful and even highly specialized gadgets have entered the U.S. market.The AMTAST TES10B is a handheld battery powered dual range teslameter that is capable of detecting fairly small magnetic fields, as well as indicating magnetic polarity of that field. With this meter, one can conduct an entire series of investigative efforts in the practical magnetics and electronics with a reasonable degree of accuracy, given the price point of this meter.The device features two display range units, the Tesla and the Gauss, which are different though related kinds of magnetic readings. The actual measurements are taken via a small hand-held probe which is small enough to fit into a variety of spaces where magnetic measurements might be needed. The probe is equipped with a protective removable cover, which is a good thing, since the probe itself is quite slender and is made of circuit board material. It would be quite easy to crush, break, or destroy this little probe, so the user is wise to take precautions as to how, where, and how roughly they utilize the probe tip when getting measurements.The unit comes with a handy wal-wart, which saves on batteries if one is using the device in a bench-only mode. It also operates on four AA sized batteries, which in my unit were included - though the seller informs buyers that "batteries are not included". Not sure, but mine had them. Anyway, the unit operation is quite straightforward, and the manual includes enough information to get you on the road to measuring magnetic fields with reasonable accuracy. The display is large and easy to read, and the various modes are obvious and responsive to push-button commands. The display has a backlight feature that is selectable, and the two SI (tesla and gauss) units are selectable via their own dedicated pushbotton as well.The case is made of the usual and popular hard plastic that dominates instruments of this class, and is completely conventional in design. It is reasonably robust, though one would excercise reasonable care in handling. It is not something to toss in the bottom of your toolbox, especially not the probe, which has a protective cover that should always be kept in place when not measuring, or YOU WILL BREAK THE PROBE! you have been warned. :-)The entire system comes in a nicely put togther blow mold plastic case which I particularly appreciate as it has specific cut foam locations for each tool part, as well as actual pin-hinged latches, as opposed to those one-piece molded snaps that always seem to break off after a few years.The weakest point in the entire device is one that is actually good for a few laughs. I'm speaking of the "instruction manual". This manual is obviously translated from Chinese to English (sort of) by a machine, and then not proofread by anyone native or trained in the English language.As a consequence, it contains dozens of linguistic howlers that make for great fun reading. Ultimately, it does get the job done of explaining the unit, though not without a few head scratching moments - most of which are sure to bring a smile to any native English speaking person's face.Overall, I rate this device five stars - for what it is. A practical low-cost and reasonably accurate hand-held teslameter that can provide lots of quick answers to anyone working with magnetic fields and magnetic devices where polarity matters.Recommended for guitar technicians who need to confirm pickup polarity as well as magnetic strength. Also good for those building anything with magnetic sensors, as well as those working on devices where stray or excessive magnetic fields can damage or cause operational malfunction. Data centers, tape storage locations, electronic technicians working with transformers and electrical systems subject to high amounts of stray magnetism. All these types and more can benefit from this handy and easy to use tool.FIVE STARSPros: Reasonably priced, easy to understand and operate, portable but also bench powerable, large easy to read display, rapid power-on cycle, nice protective case.Cons: probe is small and fragile - exercise caution when using. Range of sensitivity is fixed - and while useful for that range, the inability to auto-range, or manually jump ranges means that very low stray fields might be missed, while very large and strong fields will overwhelm the device's ability to give a useful reading.

Um die Meßgenauigkeit des Geräts zu prüfen, habe ich eine exakte Referenzspule hergestellt mit folgenden Daten: 73 Windungen Kupfer-Lackdraht 0,4mm, Wicklungslänge 35mm, Spulendurchmesser 12,4mm (genauer 12mm-Wickelkörper aus Kupferrohr+ 2* halber Drahtdurchmesser), Stromstärke 0,1A (+/- 0,1%), wicklungsparalleler Schlitz 1,3*4mm in der Mitte der Wicklung zum Einführen der Meßsonde genau in das geometrische Zentrum des Spulen-Innenraums. Die Physik liefert für eine solche Spule bei dem Strom von 0,1A eine magnetische Flußdichte von 0,2471 mT. Der Meßwert schwankt im empfindlicheren Meßbereich in der Praxis etwas zwischen 0,250 und 0,260T, was wohl auch auf Störfelder in meiner Elektronik-Werkstatt zurückzuführen sein könnte. Zur Kontrolle habe ich die Sonde auch um 180° gedreht. Alles zusammen hat also zu dem genannten Fehler von 0,0529T geführt, was 5,2% entspricht. Das ist zwar erheblich mehr als der vom Hersteller angegebene Wert von 1-2% je nach Meßbereich, kann aber wie gesagt auch an Störungen und kleineren Fertigungsungenauigkeiten der Spule liegen. Alles in allem ist die Genauigkeit dieses doch recht preiswerten Meßgerätes für mich vollauf zufriedenstellend. Auch bei anderen Strömen von z.B. 1,2,3 und 5A (kurzzeitig) war der Fehler nie größer, eher kleiner. Auch in den Wechselstrombereichen hatte ich eher kleinere Fehler, habe aber nicht die Möglichkeit, Wechselströme auf 0,1% zu stabiliseren, was zusammen mit der Erwärmung der Spule die Reproduzierbarkeit reduziert.Wichtig ist natürlich, die Meßsonde richtig auszurichten: die Feldlinien müssen die Sondenoberfläche in allen Richtungen genau senkrecht schneiden. Außerdem habe ich meine Sonde öfter mal in einem magnetischen Wechselfeld neutralisiert, um Polarisationserscheinungen sicher auszuschließen. Dazu habe ich eine kleine Trafo-Sekundär-Netzwechselspannung an die Meßspule angeschlossen (1V reicht!), die Sonde eingeführt und sie dann langsam herausgezogen, bis sie das Magentfeld völlig verlassen hatte (10cm weit). Das war's. Wenn's keine gravierenden Fertigungstoleranzen gibt, kann ich das kleine Kästchen empfehlen.

This is my first Gauss meter that I picked up for measuring the magnet quality in my drone motors, it should also be useful in detecting the if a motor has gone bad or if it's the brushless controller. The meter comes with four alkaline AA batteries that that fit into the back of the meter, but there is also a 120v power supply included for external power. The meter comes in a fairly decent quality case that should make carrying and storage easy while protecting the meters probe which looks fragile. I tested the meter out on a cheap brushless motor and measured 345mt, which is within 15 of reading what I was hoping for. The only real downside I see is the lack of a peak measurement option.

I got this to check for magnetized heads on a tape recorder, and it seems to work just fine for that. It's not fancy, and the sensor is a bit fragile- looking but it got the job done. I have no idea if the accuracy is any good, but since I'm only interested in approximate measurements, it's ok for me.

Scratched off label? Seriously? I haven't even turned this unit on yet. Maybe I will revise this review if it turns out to perform it's intended function at a higher level, but probably not. There's no undoing the effect of seeing the pathetically unprofessionally modified housing. Regardless of how it works, this meter will always look like a second rate reject. Why in heaven's name a company would distribute products in this condition I will never understand. No way does it feel right to have paid over $100 for such sorry production. Sad thing is, they get away with it. I should return it on principle, but that's just more effort on my part. Lose lose, consumer.

check magnets from magnetic driven clocks