NIST-Traceable Flow and Pressure Calibration

Included with every Alicat flow or pressure instrument is a NIST-traceable calibration report. These reports are included to show that the device is operating within its factory specifications.

Alicat calibration reports compare the data that your device is reporting with the data reported by one of our in-house flow or pressure standards. Most calibrations are conducted at five points in the full-scale range of your flow or pressure device: 0%, 25%, 50%, 75% and 100% of full scale. In the event that you, your calibration center, or metrology lab require more or different data points, custom calibration points are available for an additional charge.

Understanding Calibration and Accuracy Specifications

Alicat offers the following factory calibrations options for most of our flow and pressure instruments:

  • Gas flow, standard accuracy: +/- (0.8% of the reading + 0.2% of the full-scale range)
  • Gas flow, high accuracy: +/- (0.4% of the reading + 0.2% of the full-scale range)
  • Liquid flow: +/- 2% of the full-scale range
  • Pressure, standard accuracy: +/- 0.25% of the full-scale range
  • Pressure, high accuracy: +/- 0.125% of the full-scale range
    • Absolute pressure calibrations (at standard or high accuracy) are also available for mass flow instruments.

Special Calibrations

Bidirectional Flow Calibration

Bidirectional flow calibration is available for flow instruments and gauge pressure instruments. Full-scale accuracy specs are generated from the entire bidirectional range, from negative full-scale to positive full-scale. For example, a 1-slpm flow meter with bidirectional calibration would have a full-scale range of 2 slpm, from -1 slpm to +1 slpm.

AFS and FP-25 Calibration

Our AFS and FP-25 instruments receive NIST-traceable calibrations for mass flow, temperature and barometric pressure. Flow calibration accuracy is 0.75% of reading for AFS and 1% of reading for FP-25.

3rd-Party 17025 Calibration Services

Alicat does not offer 17025 calibrations from our own factory, but we do partner with 3rd-party calibration houses for these services. 17025 calibrations are available with L.A.B. or A2LA accreditation.


The recommended period for recalibration is once every year for most Alicat instruments. A label located on the back of the device shows the date of the most recent calibration; this date is also stored in MENU > ABOUT > DEVICE INFO. Your instruments should be returned to the factory for recalibration near the listed due date. Please complete our Service Request Form or call us to schedule your recalibration service.

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