Product Review

Features:
Cutting Size: 45mmx26mm
Dimensions: 48mmx29mmx21mm
Power Supply: DC 3.5-30V
Voltmeter Range: DC 0-100V (resolution of 0.1V)
Ammeter Range: DC 0-9.99A (Direct measurement, no requirement of shunt)
Display: Dual 0.28" three digit LED tube
Display Color: Voltmeter Red, Ammeter Green
Refresh rate: about 500ms / times
Accuracy: + / - 1% + 2 digits

Wire Connection:
Thin Red line (VCC): Power Supply + (DC 3.5-30V +)
(if the measure voltage between DC 3.5-30V, then the Thin Yellow line and Thin Red line can connect together)
Thin Black line (GND): Power Supply - (DC 3.5-30V -), Measure Voltage - (DC 0-100V -)
Thin Yellow line (VIN): Measure Voltage + (DC 0-100V +)
Thick Red line (I+): Current Input +
Thick Black line (I-): Current Input -
More detail please check the description picture.

Error Phenomena:
Due to the aging of the device and change of ambient temperature
1. the error becomes larger when measuring small current
Solution: When there is no load, short-circuit 2 pads of KEY and then power on, the module will automatically do zero calibration, after that shut off the module and cut the short circuit point.
2. the error becomes larger in whole measurement range
Solution: When connecting load(half of the range is best), keep adjusting R7 until it displays the same value with the more advanced calibration source.

Note:
If measure the current over than 5A for long time. please welding the wires to the meter port, to avoid High impedance and unstable working.
When the power supply is greater than 24V, please connect a 1k resistor in series to increase the reliability of the product

Package Included:
1x 2in1 Voltmeter/Ammeter DC