Table Of Maximum Transmittable Frequencies For Accelerometer Cables.

Table of maximum transmittable frequencies for accelerometer cables.

Cable Capacitance (picoFarads/foot) Cable Length (feet) 16 26 30 42 10 142084 87436 75778 54127 20 71042 43718 37889 27064 30 47361 29145 25259 18042 40 35521 21859 18945 13532 50 28417 17487 15156 10825 75 18945 11658 10104 7217 100 14208 8744 7578 5413 150 9472 5829 5052 3608 200 7104 4372 3789 2706 300 4736 2915 2526 1804 400 3552 2186 1894 1353 500 2842 1749 1516 1083 1000 1421 874 758 541 2000 710 437 379 271 3000 474 291 253 180 4000 355 219 189 135 5000 284 175 152 108 10000 142 87 76 54

Calculations based on the formula: Fmax = _____10^9____ 2.PI.CV/(Ic-1) where, Fmax = maximum frequency C = cable capacitance (picoFarads) V = maximum output from sensor (volts) assumed @ 5V Ic = constant current from signal conditioner (mA) - 2.4 mA 10^9 = scaling factor to equate units PI = 3.142

The capacitive loading of the accelerometers may distort or filter higher frequency signals depending on the supply current and the output impedance of the sensor. Generally the distortion is not a problem up to about 1kHz. However, for higher frequency vibration, shock or transient testing over cables longer than about 500', there is a strong possibility of distortion.