Part of Amprobe’s popular 500 Series, the AM-520 is a multimeter for HVAC applications in commercial and residential settings. It has decent functionality and safety ratings, such that you can measure AC and DC voltage and current, along with AC and DC micro-amps and temperature.
Ideal for repairing air conditioning and heating units, the AM-520 also has extras to include a non-contact voltage detector and a built-in flashlight. The backlit screen has a bar graph and you get a hanger strap thrown in.
- Measures AC/DC voltage and current
- Micro-amps range for testing flame detectors
- Capacitance and frequency
- Non-contact voltage detection
- Auto, manual-ranging
- Temperature range in °F and °C
- CAT-IV safety rated, to 600V
- Continuity and diode tests
- MIN/MAX recording for signal fluctuations
- Relative zero mode
- Backlit display with bar graph
- Size: 7.2″ (182mm) x 3.5″ (90mm) x 1.8″ (45mm)
- Weight: 12.5oz (354g)
- Probe leads
- 9V battery
- Thermocouple temp probe
- Velcro strap
- User manual (online pdf)
In-depth Review of the Amprobe AM-520
With this multimeter, you can troubleshoot all kinds of faults: concerning thermostat temperature, startup capacitors, current draw, voltage issues, for example. In addition, the micro-amps range allows you to test the function of flame detectors on heating systems by picking up on minute current changes. There is also a battery tester, good for testing 1.5V and 9V batteries under load.
Some range values: AC/DC to 600V (CAT-IV) – current to 10A, resistance to 40MΩ, capacitance down to 10pF, frequency to 10MHz, and micro-amps to 400μA. The temperature measuring range is also quite generous and displays both Celsius and Fahrenheit – type K thermocouple included.
Non-contact voltage detection: This is a great addition on any multimeter. Although it only starts detecting AC voltages above 90V, it is good for quickly ascertaining runs in walls and whether socket outlets are live. It will detect up to 600V, but note that sensor distance is a measly 8mm.
The Amprobe AM-520 also has standard test features, such as continuity beeper and a diode checker for checking LEDS and other diodes. Unfortunately it can’t put out the voltage to check all colors, such as blue or white.
Modes: includes MAX/MIN, which is used to capture high and low values of a fast changing signal. You can also zero out the leads’ resistance with relative mode for more accurate measurements and for comparisons. There is also a display hold on the 520, albeit manual type, along with auto power-off and a torch.
|AC voltage||400mV / 600V||±(1.0%+3) @ 4-400V||0.1mV-1V|
|DC voltage||400mV / 600V||±(0.8%+1) @ 4-400V||0.1mV-1V|
|AC current||40mA / 10A||±(1.5%+3) @ 4-10A||10μA -10mA|
|AC micro-amps||400μA / 4000μA||±(1.2%+2)||0.1μA-1μA|
|DC current||40mA / 10A||±(1.2%+3) @ 40mA-10A||10μA -10mA|
|DC micro-amps||400μA / 4000μA||±(1.0%+2)||0.1μA-1μA|
|Resistance||400Ω / 40MΩ||±(1.0%+2) @ 4-400kΩ||0.1Ω-10kΩ|
|Capacitance||40nF / 4000μF||±(3.0%+5) @ 400nF-40μF||10pF-1μF|
|Frequency||10Hz to 10MHz||±(0.1%+4)||0.01Hz-0.01MHz|
|Temperature °F||-40°F to 1832°F||±(1.8%+6°F) @ 32°F-212°F||0.1-1°F|
|Temperature °C||-40°C to 1000°C||±(2.5%+2°C) @ 100°C-1000°C||0.1-1°C|
|AC ranges @ 45-400Hz|
Amprobe devices are generally well built and the AM-520 is no exception. As with the others in the 500 series, it is made in China, however, which might put some off. On the rear is a tilt stand, there are built-in probe holders, and a hanging tag on the top offers hands-free usage with the included Velcro strap. The battery is easy to get to via single screw. Inside, the input protection is there but the soldering quality could be better.
Interface and Functions
The LCD display is 4,000-count, so can show a reading to 39.99V. Not the quickest of cats, though it refreshes up to 3 times a second and is nice and clear. There’s also a fast-updating, 41-segment bar graph and a bright backlight that stays on for 25 seconds.
An auto power-off mode turns the device off after 15 minutes of non-use. There’s also a low-battery indicator and the LED flashlight atop the unit is ideal for when working HVAC in tight spaces. Most of the ranges have their own dial selector position, although it can be slightly annoying having to switch between AC and DC on voltage/current ranges.
Safety ratings are CAT-II (1000V) and CAT-IV (600V), signifying spike/transient input protection of 6kV and 8kV respectively. You can thus use this meter on outdoor service side installations up to 600V, three phase. Both the low and high amperage circuits are protected by high quality HRC fuses, to 500mA and 11A. The Amprobe AM-520 also has sound mechanical protection courtesy of a tough rubber holster.
Pros and Cons of the AM-520
- Good functionality for the price
- CAT-IV rated
- High volts/amps ranges
- Micro-amps and temp ranges
- Non contact AC voltage sensor
- Good capacitance range
- Can manual and auto-range
- Built in hang tag (plus Velcro strapping)
- Handy LED flashlight
- Slow continuity and auto range
- Voltage detector range a bit narrow
The Amprobe AM-520 review has a very capable mid-range multimeter for the general HVAC electrician. It has many nice features, such as a voltage detector and temperature range, and is good for use indoors and outdoors in the home, office, hospital or school, as well as for automotive use. It comes with a hanging strap and temperature probe, together with obligatory leads and battery.
Alternatives: If you need more functionality, range and accuracy, consider the AM-560 advanced HVAC meter from Amprobe. The Fluke 116 is also a pretty good HVAC multimeter, although it’s a significant step-up in price.