DJB Instruments (UK) Ltd products

Ultra high output, multiple shear plate vibration transducer. Shear plate construction provides near total isolation from mechanical inputs other than acceleration, thus safe guarding measurement integrity in applications where vibration is accompanied by high dynamic strain levels. Generalizing, these conditions are prevalent where modal frequencies are low, and are thus associated with vibration surveys of large structures.  Transducers exhibiting significant strain response may operate more akin to strain gauges at low frequency excitation and their use is to be discouraged.  A number of parallel shear plates equivalent in total thickness to single plate of charge sensitivity Q and capacitance C, generates charge nQ. Clearly taken to the limit, noise degradation overrides signal increase, hence these products are largely a compromise between signal/noise and mass/size. This Accelerometer is also available as an IEPE version -A1600.

The A/800 is the highest sensitivity accelerometer in the DJB range. Using multiple shear plates and large masses the 9000pC/g sensitivity makes it perfectly suited to seismic surveys and other micro g level measurement – virtual immunity to strain input side effects provides guarantee of low frequency, measurement integrity. System noise level of 10-2pC is equivalent to 1mg. With bandwidth restricted to 1 kHz, noise floor should be significantly below this.