BSIDE ACM91 Review

Editor Rating: 4.4/5

Great Product

BSIDE ACM91 Review

Reviewed by: Timothy Henderson

Last modified: May 27, 2023 @ 1:54 pm

  • Design
  • Functionality
  • Price

BSIDE ACM91 Review Summary

Packing a host of testing capabilities into a budget product, the BSIDE ACM91 is a DIY-level clamp meter that attempts to hit pro-level — but doesn’t quite reach the mark.

Available for under $50, it boasts temperature testing capabilities through its included thermocouple. Hence the unit may appeal to automotive enthusiasts. Although, with a low upper heat limit of 932 degrees Fahrenheit, it’s unlikely to appeal to HVACR contractors.

Auto-ranging permits use by novice clamp meter operatives, and its generously sized display offers fuss-free reading of testing results. Furthermore, a CAT III rating promises reassuring safety — but a restricted 300-volt capacity could be an issue in high-energy three-phase systems.

True RMS guarantees scrutiny accuracy, and a memory hold function enables effortless recall of your last reading. And, being remarkably lightweight and incorporating a rear-mounted belt/pocket clip, the tool is effortlessly portable and unlikely to induce fatigue on longer projects.

The ACM91 is a Chinese manufactured machine that hits the market under numerous brands. In addition to BSIDE — the focus of this review article — you can also obtain this unit under Thsinde, Iyugen, and Tecpel monikers.


  • Weight – 4.8 ounces
  • Voltage – 600 volts
  • Current – 400 amps
  • Safety Rating – CAT III (300 volts)


  • Auto-ranging.
  • Temperature tester.
  • Generous display.


CAT III rated.
Memory hold.
True RMS.


Narrow jaw opening.
Low upper temperature.
Restricted to 300 volts for CAT III applications.
Low 100 amp testing capacity.
Vertical display.

Features and Benefits of the BSIDE ACM91 Clamp Meter

It hails from a relatively unknown brand and is available at a budget price, yet the marketing blurb promises high-end DIY and trade contractor functions.

Does this machine have that elusive electrical spark, or is it a blown fuse? Time to dive into its features.


Impressively for a low-price-point machine, the ACM91 from BSIDE incorporates auto-ranging. This welcome function means that the unit automatically determines the display metric (tens, hundredths, and thousandths) without manual intervention.

Hence, it doesn’t matter if you have no prior knowledge of electrical capacitance, voltage, or resistance sizes — making it ideal for the complete novice. And for the trade pro, it saves valuable downtime — negating the requirement to set the measurement boundaries.

True RMS

Another surprising yet welcome feature in this budget clamp meter tool.

TRMS tech (True Root Mean Square) promises elevated precision over standard RMS machines by analyzing wave frequency variances instead of just peak readings.

This accuracy is crucial for PCB, microchip, and HVACR applications — where discrepancies in scrutiny can have detrimental effects on circuitry repair and maintenance.

If you’d like to learn more about RMS and TRMS — and why they’re vital for consideration when choosing your clamp meter — take a look at my complete guide here.

Temperature Testing

The BSIDE Clamp Meter ACM91 can investigate heat levels via its included temperature testing probes. And, while a creditable inclusion for a low-cost unit, its capabilities are seriously limited.

With a testing range from -4 to 932 degrees Fahrenheit, it’s adequate for automotive applications, but HVACR pros will most likely find it lacking. That said, it does include a fuss-free readout toggle button, allowing you to effortlessly switch from Fahrenheit to Celsius metrics.

CAT III Rating

Theoretically, with CAT III certification, the ACM91 Clamp Meter is suitable for industrial-grade three-phase systems. However, limited to 300 volts (600 volts for CAT II), contractors tackling high-energy industrial loads will consider it under-rated.

That said, it still delivers a reassuring amount of protection for home users investigating single-phase systems. If you want to discover more about CAT ratings — take a peek at my complete guide to these certifications.

Large Display

Boasting one of the most substantially sized screens in the clamp meter category — the backlit and generously proportioned digits permit easy reading. Furthermore, the large dimensions enable the display to provide two lines of information — allowing you to check AC voltage or current simultaneously with temperature.

However, to include a screen of this magnitude — while keeping the clamp meter itself compact — it’s been positioned vertically instead of horizontally. For many guys, this will not be an issue, yet it could be an annoyance for electrical testing traditionalists

Memory Hold

The ACM91 Multi Clamp Meter features a HOLD function, permitting you to recall your last investigative reading at the touch of a button.

Power Saving and Battery Management

With auto-shutoff, the BSIDE Clamp ACM91 powers down after being left idle for a significant amount of time — saving you valuable cell life. Furthermore, with a low battery indicator alert — you’re shielded against being caught mid-project with a failing tester unit.

Multifunction Capabilities

For most DIYers, the ACM91 Multi Clamp Meter offers significant versatility in its testing capabilities. By rotating the easy-turn thumb dial, you can select between capacitance, frequency, resistance, temperature, and continuity.

However, bear in mind that with a jaw testing diameter of just 0.78 inches — small by clamp meter standards — you’re restricted in the cable width you can investigate

Included Accessories

In addition to the clamp meter itself, the BSIDE Multi Clamp Meter ACM91 also arrives with:

  • Testing leads with probes.
  • Thermocouple cables.
  • Soft carrying case.
  • Screwdriver.
  • Alligator clip.

Unlike the majority of clamp meters, this particular unit doesn’t come complete with batteries.

Storage and Portability

The rear of the clamp meter housing incorporates a back clip, permitting you to hang the machine from your pocket or belt. And, incredibly lightweight at just 4.8 ounces, it’s highly portable and unlikely to induce fatigue if handled for extended periods.

BSIDE ACM 91 Digital Clamp Meter Specifications

Weight‎4.8 ounces
Jaw Size0.78 inches
VoltageCAT III-300 Volts CAT II-600 Volts
Current100 Amps
Highest Safety RatingCAT III
Size7.05 x 2.64 x 1.42 inches
Batteries2 x AAA
Batteries IncludedNo
Auto-Power OffYes
Diode TestingNo
Resistance60 MΩ
Frequency60 MHz
Capacitance600 µF
Temperature Range-4 to 932 degrees Fahrenheit

What Do Users Say About the Clamp Meter ACM91 BSIDE?

In my opinion, the ACM 91 from BSIDE is a comprehensive DIY-grade clamp meter that, while offering some high-end features, lacks the range for the true trade pro.

Yet, not utilizing this device on a day-to-day basis, my experience is limited. Hence, to guarantee a completely thorough BSIDE ACM91 clamp meter review, I explored the owners’ opinions of this electrical tester.

Happily, their views were similar to my own and gave a generally positive opinion. These guys praised the inclusion of temperature testing, welcomed the novice-friendly auto-ranging feature, and lauded the accurate True RMS tech.

Admittedly, there were a few criticisms. Frequently mentioned were the narrow jaw size, low CAT III voltage rating, and less than robust build.

However, all owners concurred that the BSIDE Clamping Multimeter ACM91 was packing an impressive array of features in a budget unit — and was more than suitable for the home operator.

Alternatives to the BSIDE Clamp ACM91

Not exactly what you’re looking for in a clamp meter? If the ACM91 from BSIDE is not stimulating your clamp meter libido — stick with me.

I’ve put together three alternative machines that may be more suitable for your job demands and personal preferences.

AstroAI DT201D

If you welcome the temperature testing facility of the ACM91, yet are concerned that the heat range is insufficient for your HVACR applications — this machine may be more appealing.

While the DT201 offers similar features to the BSIDE — including TRMS, auto-ranging, and a backlit LCD screen — it can test up to 2000 degrees Fahrenheit, compared to the comparably restrictive 932 degrees of the ACM91.

  • Easier on the wallet than the BSIDE.
  • Greater jaw capacity — 1.65 inches, in contrast with the ACM91’s 0.78 inches.
  • MIN/MAX feature — not included on the BSIDE.
Should your projects require the epitome of precision — the omission of low-impedance testing in the ACM91 may be a downer. If this is an issue, I recommend taking a look at this clamp meter instead.

The KAIWEETS Clamper HT206D boasts this accuracy-enhancing tech, enabling you to search for ghost or stray voltages that could impair your circuitry scrutiny. This may make the machine more appealing for HVACR pros, who require low-impedance checking in their daily work.

  • Comparable price point to the BSIDE.
  • Tests diodes — not a feature of the ACM91.
  • Incorporated flashlight, not included on the BSIDE.

Extech MA440

If you’re looking for a comprehensive budget multimeter, yet are disappointed that the BSIDE lacks non-contact voltage (NCV) detection — check out this machine from the US-based Extech.

With NCV, the MA440 alerts you both visually and audibly of the presence of live wires and components without having to touch the clamp onto the circuit. This may prove a welcome safety feature for DIYers and multi meter novices.

  • 1.2-inch jaw, wider diameter than the BSIDE.
  • Similar cost to the ACM91.
  • Includes batteries — unlike the BSIDE.


Affordable, and with a host of features not typically seen on budget units, the BSIDE Clamp Meter ACM91 is a suitable machine for the novice user and amateur DIYer.

TRMS tech promises accuracy, while its temperature testing capability permits use in automotive applications. Auto-ranging allows effortless use by the inexperienced operative, and its generous display offers fuss-free reading.

What lets this machine down for the trade pro, and makes it a purely DIY unit, is its restrictive range in all areas — a narrow jaw mouth, low upper-temperature limit, and minimal voltage on CAT III systems.

However, for a multi-function multimeter for the home-improver that isn’t going to hurt the bank balance — I suggest checking out the BSIDE ACM91.

BSIDE Multimeter Clamp Meter ACM91 FAQs

Q: Where Can I Buy the BSIDE Multifunction Digital Clamp Meter ACM91?

The Clamp Meter ACM91 from BSIDE is a budget machine that offers TRMS, temperature testing, and auto-ranging. To purchase this unit, click here.

Q: Is the Multi Clampmeter BSIDE ACM91 Made In the USA?

No. The ACM91 from BSIDE is manufactured in China.

Q: What Is the Price of the BSIDE Clamper Multimeter ACM91?

The ACM91 Clamp Meter is a budget machine that targets the DIY user. To check out te current cost of the BSIDE ACM91.

Q: What Batteries Do I Need for the BSIDE Clamp ACM91 Meter?

The BSIDE Clampmeter ACM91 requires 2 x AAA batteries. These power cells are not included with the unit purchase.

Q: Can I Test Temperature With the BSIDE Electrical Digital Tester ACM91?

Yes! The ACM 91 BSIDE arrives complete with a thermoprobe, permitting you to test heat levels from -4 to 932 degrees Fahrenheit. Furthermore, a toggle button enables you to switch from Fahrenheit to Celsius readings.

Q: Where Can I Find the ACM 91 Manual?

Currently, it appears that there are no manuals online for the ACM91 Clamp Meter.

Q: Does the BSIDE Clamp ACM91 Meter Have TRMS?

Yes! The ACM 91 from BSIDE has True RMS — offering greater accuracy than other budget machines that only have standard RMS tech.

Q: Where Can I Buy Probe Leads for the BSIDE ACM 91 Clamp Meter?

There are no branded BSIDE probe leads currently available online. However, as this machine utilizes a standard fitting, you can use third-party cables with this unit.

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