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The HM675 and HM685 Hydronic Manometers are used to balance hydronic heating and cooling systems, check pump performance and to set balancing valves. They can measure and display differential, high side and low side pressure simultaneously, without having to change hose connections or instrument valve settings. Each model features a backlit display and operates on four alkaline or NiMH rechargeable batteries.

Features and Benefits

•     Measure and display high side, low side, and differential pressure simultaneously from 0 to 300 psi (0 to 2,068 kPa)
•     Robust, splashproof case
•     Inputs for two temperature probes

Features and Benefits (HM685 only)

•     Calculates flow using valve manufacturers’ Cv (Kv) factors
•    [up to 100 Cv (Kv) can be entered]
•     Calculates heat flow, impeller diameter and brake power
•     Stores up to 4,000 data points to memory for later recall/download
•    to a PC using CompuDat USB Software and USB interface cable
•     Intuitive menu structure for easy navigation and instrument set up


•     Test and balance heating and cooling systems
•     Check pump performance
•     Set balancing valves

HM675 kit includes hard carrying case, (2) 6.7 ft x ¼in. 
(2 m x 6 mm) hoses with shutoff valves, 
(2) B&G readout probes, 
(2) P/T gauge adapter probes, and power cord.

HM685 kit includes all items in HM675 kit, plus a temperature probe, CompuDat USB downloading software, and USB interface cable.

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