The UNI-T UT71E is for those electricians, engineers and hobbyists looking for a mid-range meter that can do more than measure the standard stuff. Along with voltage, current and resistance, it can also log data and measure wattage.
It is accurate and has great resolution, with its 40000-count, dual display, plus it also comes with a temperature input and several modes. There are slightly different models in the UT71 range, though there are concerns with input protection.
Some Key Features
- AC/DC voltage to 1000V
- AC/DC current to 10A
- AC+DC measurements
- Micro-amps, milliamps and millivolts
- Measures resistance to 40MΩ
- Measures capacitance to 40nF
- Measures frequency to 400MHz
- Measures Fahrenheit (1832°F) and Celsius (1000°C)
- Measures power (watts) to 2500W
- True RMS and auto/manual ranging
- Diode and fast continuity checker
- Auto power-off, low battery indicator
- Data hold, MAX/MIN and relative modes
- Data logger with opto=>USB connectivity
- 4¾ digit dual backlit display with bar graph
- Current loop 4-20mA function
- Size: 8″ (205mm) × 3.7″ (95mm) × 1.8″ x (45mm)
- Weight: 14.2oz (406g)
- Meter and battery (9V)
- Test leads
- Alligator clips
- Temperature probe
- Opto/USB cable
- Manual and CD (with PC software)
- Power adaptor
- Carry bag
- Online uni-t ut71e manual
The UT71E goes beyond a standard multimeter owing to its data logger and memory storage, its power measurement feature, dual display for AC+DC readings, and the high count of the display. You also get a 4-20mA current loop for process control monitoring.
Voltage is up to 1000V on both AC and DC and current extends down into the micro-amps ranges, which is ideal for those into electronics and for HVAC technicians. Higher current is limited to short bursts and the UT71E’s high category rating (IV @ 600V) is a little spurious since input protection is lacking.
Along with resistance, you also have capacitance, frequency and duty cycle and these ranges are fairly generous. Frequency is up to 400MHz, for example, capacitance from 40nF to 40mF, while wattage can be measured to 2500W. Despite having a duty cycle range, it’s a bit naff as it only handles lower frequencies.
This meter is also aimed at electricians who require accurate AC readings, being a True RMS tester that can show variable frequency drive output values. Continuity tests are responsive and are audible. There have been reports of it being sluggish, though this could be down to the leads not being seated properly.
Modes: MAX/MIN mode lets you see highs and lows in signals and relative lets you compare a stored value. Relative also zeroes the leads’ resistance, though only works in manual range.
|DC voltage||400mV / 1000V||±(0.025%+5)|
|AC voltage||4V / 1000V||±(0.4%+30)|
|*DC current||400μA / 10A||±(0.1%+15)|
|*AC current||400μA / 10A||±(0.7%+15)|
|Resistance||400Ω / 40MΩ||±(0.3%+8)|
|Capacitance||40nF / 40mF||±(1%+20)|
|Frequency||40Hz to 400MHz||±(0.01%+8)|
|Temperature °F||-40°F to 1832°F||±(1.5%+50)|
|Temperature °C||-40°C to 1000°C||±(1.0%+30)|
|Power (50-250V AC)||0.1W to 2500W||±(2.0%+10)|
|Duty cycle||10% to 90%|
|Current: 10A max for 10s at 15-minute intervals, 5A continuous|
Power tests: Unheard of on multimeters in general, it lets you measure power output between 50V and 250V via the included adapter which plugs across the jack inputs. Wattage is up to 2500W and although the resolution isn’t great (0.1W), it’s a useful feature nonetheless.
Data logger: The UNI-T UT71E has a built-in RS232 interface and can continually measure events that can be transferred to PC via the optical output/USB. Events can be logged up to 255 seconds. The meter will store 100 measurements and software is included for computer analysis. Lengthy monitoring will rundown the battery as there is no independent power input.
UNI-T is one of the better Chinese brands and the UT71 is quite well built. The case is strong, albeit with an integrated cover which is not as durable or shockproof as the independent rubber ones. The dial selector and jack input sockets could be more substantial. The leads are typically silicone and come with attachable alligator clips.
The battery is accessible via one screw/nutsert, though the fuses require getting into the case. External build quality is let down by the lack of attention to detail on the circuit board. Input protection isn’t as good as the UT61, for example.
Display and Function
The dual display is a big plus, which is 40000 counts (4¾ digits) and measures around 3″ x 2″. You can get three measurements on the screen at one time and display AC+DC tests. It is backlit and has a 40-step bar graph, although refresh rate is sluggish at around twice per second. Good meters are up to four times per second.
The interface could be a bit clearer, yet many of the dial functions have their own position, including watts, capacitance, voltage and millivolts. DC and AC voltage is shared. Getting the buttons figured out can also be tricky at first, with more than one function on each. Hold is shared with Peak Hold, and Recall with Store, for example.
The dial selector beeps when you turn it, which might get annoying. There is a jack input warning, which beeps when you plug in wrong for a given dial range. While the continuity checker is quick, it can be inconsistent, which might be down to the seating of the leads.
There is a lack of input protection on the UNI-T UT71E, with just a PTC and cheap glass fuses. It is rated to CAT-IV 600V, CAT-III 1000V (signifying 8kV surge protection), but going up to these energies is not recommended, and certainly not at significant amperage.
Overload protection: current ranges are fused to 500mA and 10A.
UNI-T UT71E PROS
- Timed data logging with 100 memory storage
- Computer software included
- Micro-amps range
- Hi-res display shows dual measurements
- True RMS helps with AC accuracy
- Auto range default + manual ranging button
- Slow screen update
- DC millivolts only
- Iffy CAT ratings & input protection
- Glass fuses
The UNI-T UT71E review has a decent meter capable of measuring power and logging data. It measures most ranges fairly accurately and is pretty quick on continuity checks. The screen is high resolution, but it shouldn’t be used on high power systems. Some of the Uni-Ts can be inconsistent and there could be reliability issues due to the use of potentiometer trimmers on the board.
Others in the UT71 series include the A, B, C and D. There are subtle differences between the models. All are TRMS data loggers and offer the same accuracy. The UT71D has more memory, the base UT71A&B have a 20000-count screen instead of 40000, while the UT71E is the only one with a power measurement feature.
Alternative: There are few alternatives if you need a wattage and data logger on the same unit, aside from the Gossen Metrahit, which is very expensive.