Instrumentation

Points to consider

This guide outlines the differences between the types of accelerometers available.

Charge or IEPE

If you are using a charge accelerometer you will need a charge amplifier.  Very few data acquisition systems offer built-in charge conditioning so an external box will be required. IEPE accelerometers can often be connected directly to the acquisition system as the IEPE power is available, an ideal way of minimising hardware needs.  If an older acquisition system is used, a range of IEPE signal conditioners is available from battery-powered/DC supplied to rack Base multi-channel solutions.

Inline charge amplifier 

This is becoming a very popular way of connecting charge accelerometers, utilising the IEPE power built into many data acquisition systems.  The fixed gain amplifier is housed in a BNC/microdot adaptor, allowing it to be connected directly to the data acquisition hardware with a low noise cable attached to a charge accelerometer.

Filters 

Analog filters enable users to filter out unwanted noise or other spurious signals. 

Integrators

Conversion of the accelerometer signal to either a velocity or displacement value is a relatively simple mathematical process.  Integrators can do this in real-time allowing the use of the already converted signal. DJB Instrumentation is available as modular systems in portable case or rack-based systems as well as fixed, single or 9-channel solutions.