The Amprobe 37XR-A is a popular DMM for troubleshooting electronics. It offers component / logic testing and is True RMS responsive, with better accuracy on a range of AC signals. The 37XR-A is good for the bench and in the field, plus its backlit screen makes it useful for low-light areas. A complementary magnetic strap aids hands-free usage.
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Key Features
- True RMS accuracy
- Measures AC/DC current to 10A
- DC voltage to 1000V, AC to 750V
- Performs component logic tests to 20MHz
- Measures inductance to 40 henries
- Modes include Min/Max/Av, Relative and Peak
- 10,000-count display with bar graph
- Auto power-off
- Leads input warning
- Battery: 9V
- Weight: 1.06lb (482g)
- Size: 7.7″ (196mm) x 3.5″ (92mm) x 2.4″ (60mm)
Includes
- Meter (+ battery) with test leads
- Alligator clips
- Magnetic strap holster
- Spare 500mA ceramic fuse
- Instructions (online manual)
Review of the Amprobe 37XR-A
Those into electronics and radio will get the most use out of the 37XR-A, which can perform both CMOS semiconductor and TTL transistor logic state tests. It can also analyze issues in a system by measuring inductance (up to 40h), as well as perform radio-frequency work with its decibel-milliwatts range.
This is a full range multimeter, with voltage, amperage and decent resistance ranges. In addition are capacitance, frequency and duty cycle, though there is no temperature input as with some of the other meters of this series. Diode and continuity testers are included on the same range position.
The Amprobe 37XR is an auto-ranging meter by default, though there are separate ranges for amps, milliamps, micro-amps and induction (H, mH). You can also go manual ranging for better response time by hitting the Range button.
SPECS
| Range | accuracy | resolution | |
|---|---|---|---|
| DC voltage | 1000mV / 1000V | ±(0.1%+5) | 100μV |
| AC voltage (45-500Hz) | 1000mV / 750V | ±(1.2%+10) | 100μV |
| Peak hold | 100V, 750V | ±(3.0%+20) | |
| DC current | 100μA / 10A | ±(0.5%+5) @ 1mA-400mA | 0.01μA |
| AC current | 100μA / 10A | ±(2.5%+20) @ 10A | 0.01μA |
| Resistance | 1kΩ / 40MΩ | ±(0.5%+8) @ 1kΩ-1MΩ | 100Ω |
| Capacitance | 40nF / 400µF | ±(3.0%+5) @ 400nF-40µF | 0.01nF |
| Inductance | 4mH / 40H | ±(5.0%+30) | 1μH |
| Frequency | 100Hz / 10MHz | ±(0.1+5) | 0.01Hz |
| Duty cycle | 0 to 90% | ±(2.0%+20) | 0.01% |
| Diode test | 1mA out | ±(1.5%+5) | 1mV |
| Decibels/mW (45Hz-5kHz) | -13dBm to 50dBm | ±(0.7dB+8) | 0.01dBm |
| Logic Tests | |||
| High | TTL: 2.8V - ±0.8V | CMOS: 4V - ±1.0V | |
| Low | TTL: 0.8V - ±0.5V | CMOS: 2V - ±0.5V | |
Modes and Performance
There are several useful modes on this digital multimeter, making it more useful than the previous four models in this series.
Min/Max: Lets you track the lowest and highest results during a measuring session. You can also get the average value between these readings.
Peak ±: For AC signals (voltage and current), peak hold will record these values, positive or negative.
REL (relative): This is known as zero mode. You can set a previous reading as the zero and then compare any deviation with the next reading. This mode will also zero out the natural resistance in a set of leads for tighter results.
Hold: Freeze the presently measured value on screen for later viewing/recording.
Sleep mode: The meter will shut itself down if not used for 30 minutes to help retain battery charge.
The 37XR-A performs well enough and compares to similar spec’d meters of other brands, as well as Amprobe’s popular AM series. As with many non-high-end devices, it does suffer a bit on the speed of its continuity tester. This is only really an issue if you’re checking multi-core cables in one hit, such as with linemen.
Battery consumption is somewhat higher on this model owing to the more power-hungry functions and the display backlight. You can expect around 100 hours’ usage, which is not great nowadays. Nine volt batteries are not as efficient as AAs regards power output.
Design
Good, sturdy design is the hallmark of the 37XR-A, with its ergonomic case and nicely fitted dial selector switch. The included black rubber holster protects all four corners and the display to a degree from bumps and drops. It is quite bulky, but this is a full size meter with all the ranges. As with the others in this series, the battery and milliamp fuse are easy to get at via a rear panel.
Display and labels: The display is not generally the strong point of these multimeters, though the Amprobe 37XR-A has a blue backlight making the digits easier to read in low light conditions. It is a 10,000-count (4 1/2 digit) display, which has a bar graphic underneath. The buttons and dial selector switch are nicely labeled, with the yellow select button extending certain range positions.
Protection
The 37XR-A is certified for CAT-III installations (to 600V) and CAT-II installations (to 1,000V). Category 2 is good for items connected to the power supply, such as appliances and air-con units, with category 3 okay for directly testing building installations. This meter is not up to industrial CAT-IV ratings and associated surge protection.
Both amperage inputs are protected by fast blow, ceramic fuses. The milliamp/micro-amp circuit is behind a 500mA fuse (order#: FP500) and the main input a 10A fuse (FP100).
Pros and Cons
PROS
- Fairly high resolution, backlit display
- Measures inductance
- Dedicated logic tests
- Min/Max, peak and relative modes
- Good electronics testing features
CONS
- Sluggish continuity checks
- Narrow capacitance scale
- No good for CAT-IV installations
Wrapping Up
If you’re looking for a handheld multimeter that can perform electronics component tests that also measures inductance, as well as measure volts, amps and resistance etc, then the Amprobe 37XR-A is a pretty good deal. The display is a bit small and fady, albeit which is backlit, plus this is a big American brand known for putting out solid equipment. if you don’t need logic and inductance, perhaps look to the Amprobe 34XR-A.
