Jim Sinopoli: BAS
Part 1: Picking the Best BAS
Part 3: BAS Sensor Calibration and Documentation
BAS Sensor Calibration and Documentation
December 2011 - Building Automation
Is there a standard for sensor calibration and/or a document that discusses best practices for sensor calibration?
The calibration of sensors, both the sensor itself and the communication back to a typical controller, is pretty important. For example, if you're getting temperature data from a sensor that's off by a couple degrees, that's going to waste energy in an HVAC system and that can mean wasting a lot of money. The rule of thumb on how often you calibrate is once every six months, however I know of organizations that have never re-calibrated their sensors.
There are several organizations that have guidelines or have demonstrated some practical applications as to how to go about sensor-calibration. They include the following:
• I'd start off with ISA, the International Society of Automation. They have some ANSI standards dealing with the calibration of sensors. It's primarily related to process and industrial automation but it has relevance for building automation.
• The second would be The National Conference on Building Commissioning. The commissioning agents have to commission systems, so they have at least written about and teamed with the Lawrence Berkeley National Lab to deal with the practical application of commissioning and calibrating sensors.
• And the third would be ASHRAE. They don't have any standards on sensors but they have particular guidelines related to specifying DDC systems and measurement of energy and demand savings.