Sensor Calibration Basics

In order for an analyst to properly perform their job, they need to have tools they have confidence in and understand how to use. One of the primary tools for a vibration analyst is a properly calibrated sensor. Every sensor manufactured at CTC is calibrated using a reference sensor that is traceable to the National Institute of Standards and Technology (NIST). Sometimes questions arise as to the importance of calibration as well as the methods we use to calibrate our sensors.  

Calibration Process 
Once the sensor assembly is completed it is processed for calibration. At this point, every sensor is already engraved with a part number and serial number. The calibration technician selects the sensor model, enters the serial number into the computerized calibration system, and then mounts the sensor to be calibrated to a “reference sensor," which is calibrated annually by a third party. The reference sensor is mounted to a reference shaker, also calibrated annually, and traceable to NIST. 

The whole assembly is then shaken at several frequencies along the sensor’s range to ensure that the output of the sensor falls within the sensor’s specified tolerances. The actual sensitivity of the sensor, as measured at 100 Hz RMS, is then printed on a calibration sticker, along with the model number, serial number, bias voltage, and date/time tested. 

Calibration Options 
CTC provides every sensor with a standard CA10 single-point calibration sticker enclosed with the sensor when shipped. CTC also offers an annual single-point recalibration for all sensors at no charge other than shipping costs. 

Other Calibration Services 
CTC offers more detailed calibration options for an additional charge. Multiple points are processed, plotted, and graphed against frequency. This information can be valuable for advanced analysts. For more information, please contact your CTC sales representative.