Each Emprise anemometer is calibrated in our in-house wind tunnel over a range of 5 to 90 ft/s (1.5 to 27 m/s). The calibration yields coefficients for an mX + b equation to convert the anemometer’s output frequency to air velocity. Download an example calibration certificate.
The wind tunnel is a 16’ long x 10” diameter duct with two identical bell mouth contractions separated by a 6° diffuser and settling chamber. Air speed is controlled by a variable frequency drive controlling the centrifugal blower.
The anemometer being calibrated is mounted at the throat of a wind tunnel’s inlet bell mouth. A reference anemometer is located in an identical bell mouth located downstream. The reference anemometer is an Emprise 5”, 8 blade unit with 16 pulse/rev resolution. The reference anemometer is calibrated annually by Dick Munns Company. The rated uncertainty for the reference anemometer is ±0.5% of reading.
Emprise offers re-calibration service on our anemometers. The frequency of calibration is up to customer but most customers opt for annual calibration of their anemometers. The calibration service includes inspection, cleaning, testing of the electronics and new bearings. Calibration turn-around is typically one week. Contact Emprise at +1-800-278-2119 for current lead-time and pricing.