Review on Dwyer 2000 00 Magnehelic Differential Pressure: Your Ultimate Solution for Precise Pressure Measurement by Evan Zurlo

This is the second product I have purchased. This device has the lower range required for my needs. I use this to detect filter changes in my air conditioner. As soon as the pressure increases by say 15-20 percent, I change the filter. This allows me to keep the static pressure below the 0.60 IWC that was specified when my air conditioner was installed.