An auto-ranging, auto-detecting, voltage-sensing pocket multimeter, the PM55A DMM has a lot going for it. This iPhone-sized tester can do most of what standard, full-sized multimeters can do and yet, standing a mere 4.4″ from top to bottom, it easily fits into overall pockets, kitchen draws and laptop bags.
Everything from voltage and milliamp current to resistance, capacitance and even frequency can be measured, and to a fairly high degree of accuracy. The Amprobe PM55A review also reveals a nice, 6000-count display and an intuitive, uncluttered dial. Its auto MAX-HOLD function can be especially handy and this mini Amprobe is rated to CATIII 300V.
- Measures AC/DC voltage/milliamps/micro-amps, resistance
- Measures capacitance
- Measures frequency
- Continuity with beeper
- Non-contact voltage sensor (VolTect™)Detects AC/DC volts or resistance (AutoTect™)
- Rated to CATIII (to 300V), CATII (to 600V)
- MAX HOLD function
- 6000-count display
- Auto power off
- UL listed
- Size: 4.4″ (112mm) x 2.1″ (53mm) x 0.4″ (10mm)
- Weight: 3oz (78g)
- Pocket multimeter
- Test leads (hardwired)
- Silicone boot
- Carrying case
- 3V coin battery
- User manual
In-depth Review of the Amprobe PM55A
The PM55A has a lot plus points, not least its tiny size and big feature-set. This device is less than 4.5″ high and weighs only 3oz, but can measure all the important ranges and boasts extra features not normally incorporated into pocket meters. These include voltage detection, auto voltage/resistance detection and a ghost-voltage screen function.
It is an auto ranging multimeter with nine functions, to include volts (to 600V), amps (to 2mA), resistance (to 6MΩ), frequency (to 30kHz) and capacitance (to 2,000μF). The ability to register micro and milliamps is especially useful, beings as many pocket meters don’t offer this feature. There is also a diode test and audible continuity feature.
BASIC RANGES, ACCURACY
DC volts – to 450V: ~±1%
AC volts – to 600V: ~±1.5%
DC current – 400µA / 2mA: ~±1.5%
AC current – 400µA / 2mA: ~±1.8%
Resistance – to 6MΩ: ~±2%
Capacitance – 100nF / 100µF: ±3.5%
Frequency – 10Hz to 30kHz: ±0.5%
These accuracy figures are estimates and don’t take into account a given range or count/digit offset. While full size multimeters are usually more accurate, this is a pretty good effort for a test meter of this size.
AutoTect™ / LoZ
The PM55A DMM is a smart Amprobe multimeter which can automatically detect whether it is measuring volts (AC or DC) or resistance. AutoTect will display the correct reading without interaction. This feature comes with low input impedance (LoZ), which zeroes out any leaking ‘ghost voltages’ from neighboring circuits.
Non-contact voltage detection on a pocket multimeter is a fantastic feature to have on any device. It can discern voltage between 20V and 285V and comes with a beeper and bar graph display that determines the voltage (or field strength) present. It can detect 50Hz and 60Hz frequency, so is good for both the US and UK markets.
Many small meters also don’t have this feature. While data hold is useful, most multimeters only have a manual hold function nowadays, meaning you have to press the button while measuring a signal or, if there’s no hold at all, look at the screen while measuring. This might be impossible if you’re in a tight space or low light area, for example. In the Amprobe PM55A review, you set it first and then measure, while the meter automatically locks in the highest reading it detects.
Design / Build Quality
Not only is it packed with features and usability, this UL-listed tester is also quite solidly put together. It is made in Taiwan – not China – and comes with a rugged case surrounded by a silicone boot. The 24-inch long probe leads are hardwired from the bottom of the unit, as with most pocket multimeters, and are permanently attached to the base of the unit.
The large display is another hit, while the overall size of the tester is roughly that of a smartphone. The dial selector has minimal positions, incorporating an intuitive central selector button to keep things neat and usable. To get at the battery and innards, there is a captive case screw and brass-insert combination, which is a nice touch that will last.
Display and Labels
One of the standout features of the PM55A – apart from the overall size of this quality meter – is the large, 6000-count display. It is 3 5/6-digit, meaning it can display 59.99 units prior to a range change. Many full size multimeters don’t even have this kind of resolution. All icons are clearly displayed onscreen, including V, µA, Ω, nF, LoZ, AUTO, low battery indicator, etc.
It has a neat looking interface in general without the clutter that regular meters tend to have around the dial. In addition, you can also reference the rear of the meter for instruction.
Function and Performance
The PM55A comes with nine measurement functions through a combination of the input dial and select button. Be aware that there are no banana plug jack inputs on this Amprobe pocket multimeter, or separate input for the milliamp circuit. The probes are hardwired to the unit as with most pocket meters.
Of performance, the auto ranging feature is quite fast and the meter fairly accurate overall. Continuity measurement is also quick and, in general, it is faster than many compact multimeters. Both AutoTect and VolTect work well, and the MAX HOLD function can be a life-saver in tight spaces. Also of note is the auto power-off mode, which turns the device off after 10 minutes of idle time.
This tester meets IEC safety standards and is UL listed. It is certified for CATIII work up to 300V and CATII to 600V, covering it for mains installations and home appliances. The case is made of touch plastic and it features a black silicone holster around the edges to help protect from drops.
Best Suited To?
This meter is ideal for general purpose home electrics, electronics and vehicle repair work. It is also a very handy little device for professional HVAC tasks as you can easily carry it into tight spaces, plus it measures most important things. In plant maintenance, it can be good to keep in the pocket for nominal work, alongside a full-service multimeter for heavier motor/pump, panel board test jobs.
Amprobe PM55A Pros and Cons
- Measures all the important things, including capacitance
- Measures milliamps and micro-amps
- Non-contact voltage detection
- Auto volt detection with LoZ function
- Decent accuracy – around 1.5% across functions
- Small and thin – only 4.4″ high
- Large, easy to read display
- Does what most multimeters can do
- Silicone boot
- Made in Taiwan
- Hardwired leads (negative and positive)
- Un-booted probe tips
- Shame it’s not in a nice plastic case
- More expensive than other pocket meters
Although more expensive than other pocket multimeters on the market, you really do get what you pay for. This is a good brand name with a good reputation and this Amprobe PM55A review has a tiny meter with exceptional features. The negatives are largely minor and are easily outweighed by the positives. In conclusion, this would suit just about anyone in the trade and is intuitive enough for those just starting out.
Get the PM55A at Amazon