Calibrate Charge Accelerometers with Portable Calibrator
Why Calibrate Charge Mode Piezoelectric Sensors?
- Confidence in the accuracy of vibration sensors is key to aircraft fleet readiness, and testing sensors with a Portable Vibration Calibrator (PVC) leads to
- Reduce Mean Time to Repair (MTTR) and Mean Time to Test (MTTT): Could that vibration alarm be the fault of vibration sensors with amplified output? No need to send sensors off for testing. Bring a PVC right to the location of the sensors and test in minutes.
- Increase aircraft reliability: Much like those used in industrial applications, charge sensors used in aviation must endure challenging conditions.
- If the sensor is providing an amplified signal, the aircraft is grounded while technicians replace supposedly faulty components and chase balancing issues.
- If the sensor is providing a reduced output, dangerous levels of aircraft vibration can be masked, and flight operation may be unsafe.
- Confidence in the accuracy of vibration sensors is key to turbine uptime: Sensor failure/inaccuracy during turbine startups cause costly false trips.
- Cost savings: The high cost of charge sensors means annual replacement can be a huge unnecessary expense.
VIDEO: How to Calibrate Charge Accelerometers
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How to calibrate a charge accelerometer with a Portable Vibration Calibrator
Note that the PVC can calibrate both single-ended and differential output charge mode accelerometers.
Charge Mode Accelerometer Applications
Charge mode piezoelectric accelerometers offer high performance for precision vibration measurements in high temperature environments. Charge mode accelerometers are often used to monitor vibration in aircraft and ground-based gas turbines. Applications include:
- Monitoring and minimizing airframe vibration
- Propeller balancing
- Engine vibration monitoring
- Helicopter Health and Usage Monitoring Systems (HUMS) and helicopter Vibration Health Monitoring Systems (VHM)
- HUMS Gearbox vibration monitoring
- Engine testing
- Gas turbine vibration monitoring
Charge mode sensors are used in conjunction with a charge amplifier and charge converter, which convert the charge signal to a measurable voltage.
Charge output accelerometers can be quite costly, sometimes as much as $3000 to $5000 per sensor. They are often replaced unnecessarily or sent out for recalibration. With a Portable Vibration Calibrator Model 9110D from The Modal Shop, these sensors can be tested in-house. The PVC can be brought to the site of the sensor itself, saving the time and expense of an outside calibration and possibly saving the expense of a new sensor.
Portable Vibration Calibrator Model 9110D and Accessory Details:
- The calibrator is shipped with a mounting plate that handles all ARINC mount sensors (ARINC 3 point mounting)
- The PVC does not use an integral charge amplifier, so the system can calibrate single-ended charge accelerometers, and it can also calibrate differential output charge accelerometers
- Calibrate the charge accelerometer standalone, or calibrate the sensor and charge amplifier as a pair
- 9100-HTCHRGKIT charge converter (calibrated to three decimal places via a calibration process accredited by A2LA) is available as an accessory. This kit comes with a cable that mates to your sensors and terminates in a BNC
- The PVC works with a differential remote charge converter
- Model 9110D has best accuracy of any PVC on the market today (validated by A2LA-credited calibration process). From 10 Hz to 10 kHz Model 9110D is accurate to +/- 3%, and from 5 Hz to < 10 Hz, the accuracy is +/- 5%
- The internal shaker of the Model 9110D has been calibrated against a laser-primary calibration system and can easily be checked for accuracy in the field
- See Model 9110D for more information on the Portable Vibration Calibrator
What types of charge sensors can be calibrated with a Portable Vibration Calibrator?
Model 9110D Portable Vibration Calibrator can help you create calibration certificates for a wide variety of charge accelerometers including ARCINC mount sensors and integral hardline cable sensors:
- B&K: 8315, 8324
- Bently Nevada: 330450, 330750, 350900
- CEC: 4-123, 4-125, 4-126, 4-128, 4-130, 4-137, 4-138, 4-170, 4-171
- Dytran: 3085C and 3235 series
- Endevco: 6233C, 6222M, 6222S, 6237, and 6240 Series
- Metrix: 5485C, SA6350
- PCB Piezotronics: 357 & EX600B series, EX615A42 and EX619A11
- Vibro-Meter: CA 134, CE 134, CA 202, CA 280, CE 281, CA 303, CA 306, CE 311