EHDIS LCD Digital Dual-Port Manometer Air Pressure Switch Gauge Differential Tester with 11 Units of Measure ± 13.78kPa ±2 psi

It literally worked a single time. Took it out the box, installed the battery, turned it on, and noticed the calibration was off. Turned it back off to read the manual as to calibration, and now when I turn it back on, the screen flashes all symbols for about a second, and then goes dark. Taking out the battery and re-installing lets me see all the symbols again, but the unit is effectively a brick.

Ok

Works great!Using to test AOS in Porsche 911s with M96.x.

works great with my bipap

Unit seems to have no way to zero calibrate. Mine arrived with a -0.5 inH2O. This is obviously due to the fact that it was calibrated at the Chinese factory, which was located at a higher atmospheric altitude then my location of 500 feet AMSL. To get an accurate reading you will always need to remember to subtract the offset value. One trick I found was to use it in the dual input differential mode, which compares the 2 inputs, one of which I have nothing connected. This trick will show you your true value against the surrounding atmospheric pressure.

Entry level unit. Was received off spec/zero. Does not zero/calibrate as per cheesy butchered English instructions. Unit values constantly drifts. Skip it and move on.

HVAC guy installed the air circulator heat exchanger, but never adjusted the exhaust and the intake. So this device did the job

I bought this for my father, (journeyman for 30+ years) said it was decent quality and did everything it should. Had to be calibrated for proper measurement as it was off a few inches. All in all good product that’s worth its price.

Works well for balancing my Venmar.The tubes for it were incredibly short (6 inches each). Had to buy some 1/4" tubing so that it would reach the ports I needed.Works well.