Fluke 718-300G Fluke 718 Users Manual - Page 16

718 Series Users Manual Switch Test To perform a switch test, do the following: Note This example uses a normally closed switch. The procedure is the same for an open switch but the display reads OPEN instead of CLOSE. 1. Connect the Calibrator mA and COM terminals to the switch using the pressure switch terminals and connect an external pump between the Calibrator and the pressure switch. The polarity of the terminals does not matter. Note If using an external pump, connect the pump to the Calibrator and to the input of the switch using a tee fitting. 2. Make sure the vent on the pump is open and zero the Calibrator if necessary. Close the vent after zeroing the Calibrator. 3. Press S to enter pressure switch test mode. The Calibrator will display CLOSE instead of a mA measurement. 4. Apply pressure with the pump slowly until the switch opens. Note In the switch test mode, the display update rate is increased to help capture changing pressure inputs. Even with the enhanced sample rate, pressuring the device under test should be done slowly to ensure accurate readings. 5. OPEN is displayed once the switch is open. Bleed the pump slowly until the pressure switch closes. RCL appears on the display. 6. Press S to read the pressure values for when the swith opened, for when it closed, and for the deadband Hold S for 3 seconds to reset Switch Test mode; hold any other key for 3 seconds to exit. 8