Auto-zero function ensures ultra high accuracy from inline strain gauge amplifier

The patent-pending feature is initiated before measurement either using an integrated push-button or remotely via a grounding pin. This function provides a zero reference within ±1.5mV of true zero as well as correcting for zero errors due to mounting stresses or misalignment. Long term drift errors are corrected in real time so that the device is zeroed out prior to operation.

The high measurement resolution and wide bandwidth of the new Model 142 makes it useful in a number of data acquisition and instrumentation systems handling a high dynamic range, such as static force testing, load monitoring and strain measurement.

Designed to interface with quarter-bridge strain gauges, the inline amplifier is housed in a 57mm x 25.4mm x 14mm anodised aluminium case.  When shipped from the factory, the Model 142 is configured to interface with a 350ohm strain gauge, but the user can change an internal resistor to match a different type of strain gauge, if desired.

The noise level of the amplifier is exceptionally low with an RTI value of 30nV/rt-Hz.  The unit features five user-selectable gain settings, from x10 to x500, with an accuracy of ±0.5% and operates from -20°C to +70°C over a wide bandwidth of dc to 100kHz.