Last week I wrote about the TSI HM675 Hydronic Manometer 
. Today I will be discussing its older brother the TSI HM685 Hydronic Manometer. The HM685 manometer is an upgrade over the HM675 and has the same features but with a few upgrades. First the HM685 can calculate flow, heat flow, impeller diameter and brake power. This unit is also a data logger and stores up to 4,000 data points on the internal memory that can be used with the provided CompuDat Downloading Software. Additionally, the TSI HM685 also includes a Temperature Probe. This is the perfect manometer for any technician looking to upgrade their hydronic manometer.
Cheers and Happy Testing,
-Sam