Reading a Keyphasor® Tachometer Signal with a vb Instrument
QUESTION
I have a permanently installed online monitoring system. How can I connect my vb portable instrument to the buffered front panel jacks?
ANSWER
If your machine has a proximity-probe based tachometer sensor, such as a Keyphasor®), you can use this as the tachometer signal for your vb instrument. The sensor should have a buffered front-panel BNC output to ensure the vb instrument's measurements can't interfere with the online speed measurements. You will need to purchase an accessory cable for your vb instrument. If yo have a vbClassic, purchase the 3 meter Keyphasor® tach cable (Product code: CABK0108). If you have the new vbSeries instrument, purchase the 2 meter cable (Product code: KEY70258).
SETUP
Adjust the Keyphasor® proximity sensor gap so the driver box output is -8 V +/- 2 V (i.e. -6 V to -10 V) when the sensor is over the shaft. This is the normal mid-range position for these sensors. When the sensor is over the keyway its output will be -14 V to -22 V, depending on its make and model.
FAQ ID: 1309 Last Reviewed: 16 October 2006