EHDIS Manometer, Professional Air Pressure Meter, Dual-Port HVAC Digital Manometers Gas Pressure Tester Differential Gauge

This micromanometer was an excellent investment for diagnosing issues with my radon mitigation system. Despite its budget-friendly price, it delivers accurate and consistent pressure readings, making it easy to assess system performance and pinpoint any problems.The device is compact, lightweight, and user-friendly, with a clear display and intuitive controls. It responded quickly to changes in pressure, helping me identify airflow issues and ensure that the system was operating efficiently. The build quality is solid for the price, and it feels durable enough for regular use.One of the best aspects is its affordability—professional-grade micromanometers can be quite expensive, but this one provided the precision I needed without breaking the bank. Whether you're a homeowner troubleshooting your radon mitigation system or a technician looking for a reliable tool, this micromanometer is a great choice. Highly recommended for its accuracy, ease of use, and value!

I've got this manometer to measure static pressures in my HVAC system. It is small, but convenient to use. It can measure positive, negative and differential pressures. I have no way to calibrate it right now, so have to trust its readings. Today I have measured 0.43 in H2O total external static pressure in my house, which is pretty good. You can also measure pressure drops over individual system components to find a restriction.I had to buy a couple of probes for the measurements. They are typical bent tubes with small holes near the tip. The diameter of the barbs on the meter is 4.9 mm, very close to the barb size on the probes. The included silicone tubes measure 3 mm ID and 5 mm OD and fit both the meter and the probes just fine. The power comes from three 1.5V AAA cells. I have used rechargeable NiMH cells and they work just fine. For the future I can measure the pressure drop across the air filter to decide when it is the time to replace it. It is a useful tool in every household.04-27-24 update. Today I was able to calibrate (kind of) my gauge against a precision calibrated Heise gauge. I was not able to go below 6 in H2O, but from 6 to 83 in H2O both gauges showed very close numbers. It was not a proper calibration, but it showed that I can trust this gauge. It even generated an overpressure error, when I slightly exceeded 83 in H2O.

It works as it should . I adjusted my gas valve and after that the furnace worked.

I bought this because I have a 10+ year old wall-mounted natural gas heater (Empire DV-35 SG) that has very low heat output. On full heat it is supposed to have a flame this is ~ 3” tall, but all I could see was maybe 1/4” tall flame. It would cost well over $1500 to replace this unit, or probably at least $500 to have it fixed.To analyze the problem one needs to measure the natural gas pressure on the supply side of the valve, and on the downstream side (for good vid search “diagnostic testing for gas pressure and gas millivolt valves“) The heater uses a Dexen 6003 millivolt valve; this valve has small pressure taps built in to the body of the unit. The diagnostic process involves turning off the gas supply, opening the supply side pressure tap, hooking up a pressure meter to the tap, then turning the gas back on to measure pressure. Then repeating this exercise on the downstream side of the valve. Published data say the upstream side pressure should be in the range of 5 to 8 inches of water and the downstream side should be ~ 3” of water. I had the option of trying to purchase a “magnahelic” guage (high quality, but expensive), try to set up a classic U-shapped glass tube with water, or purchase an inexpensive digital pressure gage. Despite a couple of mediocre reviews for this digitial manometer I thought the purchase price ($49) was worth the risk. I am not able to calibrate this manometer, so I have to trust the readings out of the box. It gave me 5.77 inches of water on the supply side (OK reading) and 4.2” of water on the downstream side: significantly too high. I interpreted this to mean that the output tube was partially blocked and causing back-pressure, which would be consistent with the very low flame and low heat output that I saw. Upon disassembly of the output tube and orifice I found a spider had built a nest inside and almost (but not quite) totally blocked the flow of gas. I removed the tube/orifice, washed it out, and now my heater is back to working perfectly.In my opinion, spending $49 for this tool, to save a minimum of $500 and possibly more than double that, was exceedingly worthwhile. Perhaps if I were a professional HVAC person who needed a rugged, calibrated, reliable tool, this model would be too simple and maybe not robust enough. But for the homeowner / DIY person this is an excellent solution and a terrific deal.A key point to add: this unit has small diameter tubes, 3/16”, to connect to the device you want to measure. The output taps on the Dexen valve are larger, ~ 1/4” or 5/15”. I needed to separately purchase an adapter that connects the larger diameter tube to the small dia tube that comes with the manometer. Part # RMA316 at Supply House.

Simple and effective manometer. Does what it says it does

It is inexpensive, but it includes no instructions. I had to play around to figure out how to zero it and I'm not even sure if I'm doing it correctly. That is the problem with missing instructions. Unfortunately the return window had closed.

Replaced valve in modine and set my flow saved me $1000 and modine works like new! Easy to use.

I have no way to test the accuracy of it, but it does show a reading. Quality is about what you would expect from something that costs hundreds of dollars less than a pro unit. I would probably buy something more heavy duty if I was doing this for a living, but it worked fine for a one off job. Came with everything I needed and the price was really good.