Finding a quality hydronic manometer can be a tough task.
However, the TSI HM675 Hydronic Manometer is great choice. The HM675 can simultaneously measure and display low side, high side, and differential pressure. This unit also has a nice splash-proof case and inputs for two temperature probes. The HM675 reads pressure in H2O, ft H2O, psi, in. Hg, m H2O, kPa, mm Hg, bar and has a range of 0 to 300 psi. Great for setting balancing valves, checking pump performance, and balancing heating and cooling systems. When purchased, the TSI HM675 Hydronic Manometer includes a hard carrying case, 2 hoses w/ shut-off valves, P/T gauge adapter probes, power cord, and of course, the Certificate of Calibration.
Cheers and Happy Testing,
--Sam