ST1 thermal dispersion terminal box/small duct probes relate the heat transfer rate of a heated element to the airflow rate.
As the velocity across the sensor increases, the heat transfer rate increases.
The sensor probe is computer calibrated between 0 and 3,000 fpm (0 and 15.2 m/s) in individual wind tunnels to volumetric airflow standards.
As a result, performance on smaller ducts is improved by compensating for flow losses near the duct wall.
Small ducts have a large duct wall surface to free area ratio that results in higher than actual flow measurement when traditional multi-point traverse techniques are used.
ST1 sensor probes are calibrated for single, one or two sensor probe applications (regardless of the input maximum of the transmitter).
The device uses two thermistors to determine the airflow rate and temperature at each sensing point location. Accuracy is percent of reading (not percent of full scale). Performance is assured throughout the entire calibrated range.
Probes are connected to an STx102 or STx104 transmitter* or an SCN102 or SCN202 BACnet® controller, depending on the application.
Thermal dispersion technology is a significant advancement over conventional differential pressure based flow rings that are typically installed in terminal boxes and small ducts.
*Use the STx104 transmitter for network applications or if a temperature output is required.
