The capable Amprobe 38XR-A meter is the top of the XR series of Amprobe multimeters. A True RMS device with lots of functionality, to include loop current testing and RS232 connectivity, it is good for troubleshooting control systems. This is a rugged test device with a CAT-IV rating, making it okay for working in industry.
- Voltage: to 750V AC / 1000V DC
- Current: 100μA to 10A AC / DC
- True RMS Responding
- AC+DC input
- 4-20mA loop current test
- Resistance: to 40MΩ
- Capacitance: to 400µF
- Frequency (10MHz) and duty cycle
- Temperature: to 2372°F
- Decibel-milliwatts range
- Optical PC interface
- Blue backlit display
- Min/Max/Avg and Peak modes
- Auto/manual ranging
- Input warning and sleep mode
- Height: 7.7″ (196mm)
- Weight: 1.08lb (492g)
- Test leads and 9V battery
- Thermocouple (Type-K)
- Hanging strap (Magne-Grip)
- Carry case
- Users manual (pdf)
In-depth Review of the Amprobe 38XR-A
First off, this model can measure regular input ranges, including voltage, current and resistance. DC voltage is up to 1000V, AC/DC current to 10A. There is also frequency and duty-cycle, capacitance and decibel-milliwatts (dBm), continuity and diode checks, and a wide range temperature input.
It is well built and will work in many sectors, including plant maintenance, machine / panel board troubleshooting, industrial automation, HVAC industry, home and commercial electronics, auto electrics, solar, ham radio and more. The opto (RS232) interface allows the user to connect it to a PC and upload data (see below).
Ranging: The Amprobe 38XR is an auto-ranging multimeter, which works fairly quickly. If you want to manually range and step between individual ranges, the Range button lets you achieve this, too.
Modes: include Min/Max for pinning down the low and high points in a moving signal. The Peak± function will record the peak value of a positive or negative reading for AC signals. There is also a screen hold feature and a relative mode to compare a future reading.
Continuity: Unfortunately as is often the case with multimeters not in the top tier, the continuity test speed is a bit slow.
|AC voltage (45-500Hz)||1000mV / 750V||±(1.2%+10)||100μV|
|DC voltage||1000mV / 1000V||±(0.1%+5)||100μV|
|AC+DC volts (45-500Hz)||1000mV / 750V||±(1.5%+10)||100µV|
|Peak hold||100V, 750V||±(3.0%+20)|
|AC current||100μA / 10A||±(2.5%+20) @ 10A||0.01μA|
|DC current||100μA / 10A||±(0.5%+10) @ 100µA||0.01μA|
|Resistance||1kΩ / 40MΩ||±(0.5%+8) @ 1kΩ-1MΩ||100Ω|
|Capacitance||40nF / 400µF||±(3.0%+5) @ 400nF-40µF||0.01nF|
|Frequency||100Hz / 10MHz||±(0.1+5)||0.01Hz|
|Duty cycle||0 to 90%||±(2.0%+20)||0.01%|
|Decibels/mW (45Hz-5kHz)||-13dBm to 50dBm||±(0.7dB+8)||0.01dBm|
|Diode test||3V out||±(1.5%+5)||1mV|
|Temperature °F||-4°F to 2372°F||±(2.0%+4°F) @ 400-2372°F||1°F|
|Temperature °C||-20°C to 1300°C||±(2.0%+4°C) @ -20-10°C||1°C|
Display and Design
This series isn’t known for its display, yet the Amprobe 38XR-A and its sibling 37 have the best screen of the bunch. At 10,000-count, it offers pretty good resolution and also features a bright backlight and an analog-style bar graph. Response time could be better, but this is an older design.
The selector switch covers all the ranges, many having dedicated positions, including amperage, capacitance, continuity, diode, loop current and temperature. The series of eight buttons are easy to decipher and perform just the one function. With the Min/Max/Avg, simply step through.
Build: This is the best build of the series, both inside and out. It’s quite bulky and heavy, but has a lot of functions buried inside.
Current loop: Lets you read 4-20mA process loop as a percentage to ascertain system state. Works well but cannot replace a full process control meter, such as the Fluke 787.
PC connect: The RS232 port enables the sending of data over to a PC. Requires the 38SW Kit cable and software to run it.
Two fuses protect the current inputs. Milliamps/micro-amps is behind a 500mA fuse, with the amperage input to include a 10A fuse. They are high rupture capacity (HRC) fuses. Although more expensive to replace than cheap glass fuses, they are fast blow and have much less chance of exploding, destroying the meter and causing injury.
Category rating: If you’re looking at others in this series, the 38 is the only CAT-IV-rated meter, which is okay for an industrial setting. You can work at the switch room level with the 38XR-A and everything behind it. While not great for testing for parasitic draw in the auto repair world, it should be able to handle most situations.
Lead warning: Should you have the leads plugged into the amperage inputs and have the dial pointed anywhere but current, you’ll get a continuous beep.
Pros and Cons
- Great functionality, including True RMS
- Loop current tester
- Dedicated RS232 PC port
- Measures AC+DC voltage and current
- Hi Res screen (1000-count), with backlight
- CAT-IV rating
- Slow continuity
- Fairly bulky/heavy
If you’re looking for these features (current loop, AC+DC, temp, RS232), then the Amprobe 38XR-A is a bit of a steal, considering the price point compared with others with this kind of feature-set. It is also sturdy, boasts Amprobe’s reliable name and includes decent accessories, such as a magnetic hanging strap. The continuity speed and display are a slight letdown, but it is a good deal nonetheless.