TAB Technician Fundamentals Course Snapshot:  Hydronic Instruments

Hydronic Instruments As TAB professionals, part of our services require the measurement of water flows and pressures to accurately test the performance of chilled, heating and domestic hot water systems.  The instrumentation that is used for these measurements ranges from very basic to high tech.

Many years ago, bourdon tube gauges were used to measure individual pressure measurements at various points in the system.  If the component had a known pressure drop, these individual measurements could be corrected for elevation and used to establish a measured differential across the component such as a hydronic coil.  Comparing the actual differential pressure to a known differential pressure, the flow could be calculated using a fairly simple formula. Later, analog differential pressure gauges and mercury tube manometers became available that added accuracy by directly measuring the differential. These gauges had downfalls both due to the safety aspect of mercury, portability and the resolution of the analog scale.

When digital differential pressure meters became available, they revolutionized hydronic balancing. Now, with a very portable instrument, both gauge and differential pressures could be measured very accurately as long as there were pressure taps in the system. The taps were the only limitation and were typically not provided on small systems or domestic water systems.

Within the last decade, ultrasonic measurement technology has advanced significantly and become economical and user friendly for the TAB professional to use on systems that may not have pressure taps. Now, flows can be measured anywhere straight exposed pipe is available, allowing for accurate flow measurements in any size system. Our TAB Technician Fundamentals class covers all types of hydronic instrumentation. Future advanced classes will also dive deeper into the use of these instruments to accurately test all types of hydronic systems. For more information, please visit our Training page.