Model 4190 Portable Vibration Meter

The Dytran MODELS 4190 is an all solid state, battery powered. hand–held vibration meter featuring a large digital panel meter.

It converts the vibration signal from a 10 mV/g or a 100 mV/g IEPE sensor to the peak value of the vibration signals generated by these sensors.

Units are powered by two 9 Volt transistor radio batteries.

Model 4190 powers the IEPE accelerometer (10 or 100 mV/g sensitivity) with 2 mA of current at +18 Volts compliance.

The signal from the accelerometer is fed to a low–current operational amplifier gain stage which selects the gains necessary to use a 10 or 100 mV/g accelerometer. 

The next stage is a ranging stage which selects full scale ranges of 2g's, 20g's and 50g's full scale (peak) vibration ranges.

The third stage, an AC/DC converter stage, converts the vibration signal from the accelerometer to the equivalent DC peak value and displays this signal on the front panel digital voltmeter.

Additional circuitry provides low battery indication in the form of a red LED on the front panel and a "Normal Operation" green LED which indicates that the accelerometer is connected and is performing normally.

Another feature of the Dytran model 4190 is the front–panel mounted "Bias–Test" push–button.

When this switch is depressed, the front panel meter displays the voltage bias of the IEPE accelerometer connected to the 4190.

This voltage, which may vary dependant on the IEPE accelerometer chosen, will be in the range of 9 to 12 Volts DC for normal operation. 

This verifies that the accelerometer is powered and is behaving normally.

Compare this reading with the manufacturer supplied data sheet for the bias voltage supplied by the two batteries, in series (approximately 18 VDC).