Manual for the Dwyer 475-FM Series Mark III handheld digital differential pressure gauge, covering features, specs and operation.
The Dwyer 475-FM Series Mark III handheld digital differential pressure gauge is designed for field calibration, monitoring, and HVAC system troubleshooting. It measures air and compatible gases in positive, negative, or differential pressure modes with a durable molded‑aluminum housing and solid‑state circuitry.
The instrument offers dual unit selection (imperial/metric), FM certification, a 0.5" LCD display, and a standard 9 V alkaline battery that provides up to 100 hours of operation. It includes quick‑connect fittings for 1/8" and 3/16" tubing and optional accessories such as a wind‑speed kit. This manual is written in Chinese.
| Measurement range | 1 in wc (0.249 kPa) to 150 psid (10.34 bar) |
|---|---|
| Accuracy | ±0.5 % FS (60‑78 °F) |
| Temperature range | 0 °F to 140 °F (‑17.8 °C to 60 °C) |
| Battery life | ≈100 hours with standard 9 V alkaline battery |
| Weight | 10.8 oz (306 g) |
| Display | 0.5" LCD, 3‑1/2 digits |
| Power source | 9 V alkaline battery |
It measures from 1 inch water column (0.249 kPa) up to 150 psid (10.34 bar).
A standard 9 V alkaline battery provides about 100 hours of continuous use.