Description

Measurement accuracy: ±1%(10A-50A); ±0.1% (0-10A)
Refresh rate: about 200mS / times
Display: Dual four 0.28 “digital tube（blue and red）
Measuring range: DC 0A-50A.
Measuring range: DC 0V-99.9V.
Input range: DC 4V-30V
Display Color: Red(Voltmeter) + Blue(Ammeter)
Operating current: Less than 10mA
Operating temperature: -10°c -65°c
Reverse polarity protection: Yes
Weight：20g
Dimensions: 48 x 29 x 22 mm (1 7/8 x 1 5/32 x 7/8 in )
shunt: 50A/75mV
Voltage Drop: 75mV
Accuracy: Class 0.5

Package Includes:
LED DC Meter x1
Shunt(50A/75mV) x1

THE CALIBRATION OF AMP- VOLT METER
STEP 1.Open the case of the amp -volt meter, you can see a row of small holes on the side of the board, one is marked as “++”, t one is marked as “–“, and the other one is marked as “GND”.

STEP2.Power on the meter.

STEP3.Check the calibration of voltage, use proper tool to short “++” , “–“ and “GND”, the voltage display of the meter will blink which means the meter is in a statue of voltage calibration.
FOR 30V RANGE METERS:
Apply an accurate 10 V voltage to the thick red wire and black wire, then short “++” and “GND”, the meter will display 10.0U, match the actual voltage, the calibration is completed.
FOR 100V AND 200V METERS:
the calibration of those meters is divided into two sections, higher section is 60V, lower section is 5V (to keep the linear of the measurement). First, apply an accurate 60V voltage to the thick red wire and black wire, then short “++” and “GND”, the voltage display shows 60.0V, match the actual voltage, calibration is done. Second, apply an accurate 5V voltage to the thick red and black wires, then short “+” and “GND”, the meter will show 5.00U, match the actual voltag , the calibration is completed..( In the factory they have all the special tools, it is easy to carry out the above steps, but for the customer, if they do not have the proper tools it may turn out to be a little bit troublesome)
THE ANALYSIS AND RESOLUTION OF VOLTAGE VARIATION:
All our meters were calibrated when they come off the assembly line, but because of the voltage step down of the wire in actual usage (especially in those high current situation), the reading may varied from the actual voltage, this variation value can be expressed as U=I*R, here U is the voltage variation, I is the current go through the wire, R is the resistance of the wire, so if the resistance is constant, the higher the current is, the more of the variation in voltage measurement.
RESOLUTION:
Use a wire as thick as possible, or use wires with lower resistance can reduce the variation.