The perfect instrument for test and balancing HVAC systems, checking pump performance, and setting balancing valves. Provides flow and BTU/hr calculations. Measure and display differential, high side, and low side pressures simultaneously without having to change hose connections or instrument valve settings. Operates on four alkaline or NiMH rechargeable batteries.

The HM685 can display volumetric flow when a Cv (Kv) factor is entered into the instrument. Up to 100 Cv (Kv) factors can be entered. In addition, the HM685 can calculate brake power, heat flow, Cv (Kv) factors, and impeller sizing. Up to 4000 data points can be stored to memory for later recall or downloaded to a PC using this USB interface.


HM685 kit includes: Hard carrying case, two 6.7 ft x 1⁄4 in hoses with shut-off valves, two B&G probes, two P/T gauge adapter probes, power cord, and four AA NiMH batteries, a temperature probe, downloading software and USB interface cable.