Easy Calibration of Modal Hammer
G-TECH Insights Newsletter: 2016-02-17
In this latest episode of the G-TECH Insights Newsletter, we demonstrate how a calibration hammer can be easily calibrated. Plus, we report on Wilcoxon's new programmable vibration sensor.
Easy Calibration of Modal Hammer
To calibrate a modal hammer, you can use Newton's law of motion and perform a simple calibration as follows:
- Hang a mass as shown below so that it can swing freely. The frequency of the mass must be higher than the measurement bandwidth to avoid the interference of the vibrating signal.
- Install an accelerometer of known sensitivity on the mass.
- Strike the mass with an impact hammer and the force and acceleration signals are measured at the same time.
According to Newton's law of motion (ie, force = mass x acceleration), the sensitivity of the hammer can be calculated.
Impact hammer susceptibility = (accelerometer susceptibility/mass of mass) (force gauge output voltage/accelerometer output voltage)
Wilcoxon's New Programmable Vibration Sensor and Support for the 4-20mA Output and HART Network Communication
Wilcoxon launches the new PCH420 series of vibration sensors, which provides user-selectable measurement bandwidth and 4-20mA signal output, as well as support for HART protocol. Both analog and digital signals can be obtained with a single PCH420. The programmable bandwidth makes the application of vibration monitoring more flexible.