Prior to determining the relationship between the bridge voltage and the fluid velocity, the IFA-100 must be prepared for the thermal anemometer probe. These values must be entered into the IFA-100 to ensure accurate data analysis. First, the operating resistance must be set. In order to balance the bridge, a variable resistance in the bridge is adjusted to match the probe resistance. Also as part of the IFA-100 setup, frequency compensation must be performed.
Frequency compensation sets the response or gain of the probe.
The probe should respond as quickly as possible to any changes in flow conditions. If the gain is set too high, unstable oscillations occur which will damage the probe. Before any data can be taken with a probe, the operating resistance and frequency compensation must be performed. The goal of the calibration is to determine the bridge voltage-fluid velocity relationship for the thermal anemometer probe. Should any of these conditions change, a new calibration must be performed.