SENSING ENGINEERING INNOVATION CA/04/V Charge Amplifier Velocity Converter 04 system Transducer interface converts; acceleration to velocity input range 1/100pC/g; O/Ps 100mV/g and 1V/mm.sec. (max) 1/100pC/g normalizing charge amplifier input section proceeds noise limiting 10Hz 4 pole high pass filter and single integrator. Integrator converts periodic acceleration above the filter corner frequency to velocity. Integrator gain is controlled over 50dB dynamic range by 6 position switch. CHARGE AMPLIFIER Provides wideband 100mV/g acceleration proportional output when normalized, transducer sensitivity range 1/100pC/g, by means of ten-turn dial and x1, x10 multiplier. Output is independent of transducer lead capacitance. CAL input terminal allows injection of test signal, 1mV = 1pC. HIGH PASS FILTER Noise level alter integration, hence the realizable signal threshold, is proportional to fmin -n, where fmin is the high pass filter corner frequency and n is a function of the noise type, being 1/2 for that predominating in FET input stage charge amplifiers at low frequencies (<100Hz). Spurious signals also emanate from the transducer and its cable resultant upon environmental factors, and these may be considered as introducing additional f-n noise components, subject to high pass filter constraint. HP filter corner frequency is thus the determinant of threshold velocity level. INTEGRATOR / RANGE AMPLIFIER Converts acceleration input to velocity output levels of 1316mm/sec/volt in six 10dB increments. Integrator bandwidth is controlled by the HP filter integrator frequency response constraints and ultimately background noise. Peak limiting input of around 120g pk. Equates to a velocity-frequency product (v x f) of 2 x 105mm/sec2 thus absolute constraints may be readily calculated. APPLICATIONS Confined to quasi steady state inputs as emanating from vibration on rotating plant, where vibration velocity is a more representative wide band signal than either acceleration (high frequency biased) or displacement (low frequency biased), allows retro-fit of piezoelectric accelerometers for velocity transducers. Integration of transient signals, i.e. to convert to velocity change, is invalid. DJB Instruments (UK) Ltd Finchley Avenue, Mildenhall, Suffolk IP28 7BG Email [email protected] Web www.djbinstruments.com A UK company with UK-based manufacturing, assembly and calibration in-house.

SENSING ENGINEERING INNOVATION CA/04/V Charge Amplifier Velocity Converter 04 system Transducer interface converts; acceleration to velocity input range 1/100pC/g; O/Ps 100mV/g and 1V/mm.sec. (max) Single ended Input capacitance loading Normalising range Noise level @ 1pC/g, mm/sec. Rms scaling Finchley Avenue, Email [email protected] Mildenhall, Suffolk IP28 7BG Web www.djbinstruments.com A UK company with UK-based manufacturing, assembly and calibration in-house.