AC944 Series

Sensitivity is a ratio between output Voltage Vout and input acceleration. S is measured at one frequency (100Hz for CTC) and is in units of mV/g (for acceleration). The upper limit at which we specify +/-10% is based off of the sensitivity value at 100Hz.

Frequency Response (±3dB) is the range which the transducer returns a linear output signal proportional to the input between a range of +/- 3db. Conversion of % deviation to dB = 20log10(delta/reference). For example, -3dB ~ -X% and +3dB is ~ Y%.

Dynamic Range is the maximum positive/negative peak amplitudes of acceleration that can be measured without clipping or distorting the corresponding vibration signal. Important note, the maximum value is limited by the open circuit (OC) IEPE voltage (supply compliance voltage), and the negative value is limited by the bias voltage of the sensor. Exact maximum and minimum dynamic range values for a given sensor can be approximated as follows: gMAX = (VSource – Vbias)/Vsensitivity gMIN = -(Vbias - 3V)/Vsensitivity

Amount of time taken for the sensor to reach 95% of its steady state bias voltage when turned on.

Bias Output Voltage is steady state DC offset voltage on which the vibration signal is superimposed.

Maximum Shock Protection is the maximum transient acceleration force the sensor can withstand without damage occurring to the internal sensing element/electronics. Most often this occurs with portable magnet mounted measurements when the sensor/magnet assembly is not gently applied to the machine being monitored.

SIL Rating is the Safety Integrity Level that correlates to the frequency and severity of hazards. This determines the performance required to maintain and achieve safety. The higher the SIL value, the greater the risk of failure. The mean time to failure was calculated using the IEC 62380 protection method. Since the mode of operation is continuous, failures per hour is used to determine the Safety Integrity Level (SIL).