Robotbanao Dual LED 0.28” Red-Blue Display Digital Voltmeter (0-100V) and Ammeter (10A)-LED Display-Digital Voltmeter Ammeter-Voltage Current Tester

Negative voltage cannot be measured and return path current you cannot check ( these two things present it will be a higher cost in market) other than that very good product. If you want to measure current then connect the ammeter in positive side. Worth for price and delivered on time. I don't know current is not showing while taking load. But it's okay to me. I would like to measure only voltage ⚡.

The product is very good. You may find a slight difference in the amps but that can be calibrates by turning the star screw at the back labelled I. The screw labelled V is for votage, and that will mostly not need calibration. When I received the device, the amps were high by 800 mA (0.8A). After calibrating the amps is now high by only 30mA (0.03A). PS. Its not possible to calibrate the Amps to exact 0.000 if you do so the actual reading during a load test will show a lesser value. The lowesr value the amps can be calibrated to is 0.03A and the reading will always show 30mA - 60mA more. At 0.00A the reading will show 0.03A and around 1.00A the reading will show 1.06A The Meter can be connected in 2 correct circuit methods. The Thick Black wire is the Neutral Line The Thick Red wire is used to check the Amps The Thin yellow wire is to check the Volts The thin red wire is to power the meter. The thin Black wire is also neutral line but is to be only used when the meter power source is seperate from the load power source. If power source is same DO NOT CONNECT this wire any where. Also the Amp meter wire has to be connected in series AFTER the load, NOT Before else it won't work. 1. Correcting to the same power source as the Load. Here the power source has to be 4V to 30V else the meter will not work. This will help you measure voltage from 4V to 40V. Below 4V the meter will go off. 2. Correcting to a seperate power source from the Load. Here the power source for the meter has to be 4V to 30V else the meter will not work. This will help you measure voltage from 0V to 40V.

This voltmeter and ammeter combo is fantastic! The display is clear, and it accurately measures voltage and current. It’s a great addition to my toolkit. Highly recommend for anyone needing reliable readings!

Very bad product

The item is compact and looks attractive . I had to add a +15v regulated power supply to run it . The dc voltmeter reading on top part is acceptable . However the dc current reading in the lower display is no where near the actual value . I tried to calibrate it but samll trim pot on card do not allow much liberty. The reading shows much higher than actual current . Compared dc current value with a true rms DMM under different load conditions and finally i gave up. Result is truly disappointing. Finally I had to generalise by adding a multiplication factor of 0.35 to get anywhere near the actual value. Not worth as the main purpose of measuring dc current is lost.