Ashcroft ATE-100 Handheld LCD Digital Calibrator - Manual (Page 37)

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Revision 4.6 3/2004
deactivate (convert the display to mA, “------” or Volts)
the other side of the display.
PORT
SEL
Step 2 Press the mA/V key as required to change the
electrical measurement parameter to that to be used for
the switch test. Switch to Volts if the change of state will
be greater than 2 Volts; switch to mA if the change of
state will be greater than 2 mA.
mA
V
Step 3 Connect the switch electronics with a current
or voltage source, as required, to provide the required
greater than 2 Vdc or greater than 2 mA change in state.
Be certain that the change in state to be generated cor-
responds to the electrical measurement (mA or V) set up
on the display of the HHC.
Step 4 Connect the output signal of the switch to the
miniature banana jacks on the front of the HHC as out-
lined below.
For voltage: volts (V) jack and common (COM).
For current: milliamps (mA) jack and common.
Step 5 Connect the switch to a controlled pressure/
vacuum source to generate the required level of pressure
or vacuum to trip the switch.
Step 6 Proceed to Section 18.2 for trip detect testing or
to Section 18.3 for deadband testing.
Section 18.2 Test of Switch Trip Point
Step 1 With the HHC on and reading pressure or tem-
perature press the trip detect key on the keypad.
TRIP
DET
The HHC will respond by displaying the following:
Disable Manual
Deadband
Step 2 Using the left/right and up/down arrow keys
selected the word manual will flash.
Disable Manual
Deadband
Step 3 With the word “manual” flashing press the
enter key.
ENT
Step 4 Gradually increase the pressure, vacuum or
temperature until the display of the HHC indicates that a
the reading from the other module bay, if a module or an
interface module has been installed.
If the “manual” mode was selected, the calibrator must
be programmed with the reference temperature of the
external reference junction. the display will read”
Ref temperature
(A value may already be programmed, or the calibrator
may display “.0000.” Entering a new value will over
write these existing numbers.)
Program in the new temperature value of the exter-
nal reference junction, using the number keys on the
keypad. (The value that is being programmed should be
referenced to the same unit of measure that was selected
for the readout).
Press the “enter” key.
ENT
The calibrator will now return to the real-time
measurement.
When the base unit is turned off and turned on again, it
will have “remembered” the selections that were made
during the previous entry process, and default to those
parameters (refer to Appendix C for specifications).
Section 18.0 Pressure and Temperature
Switch Testing
The HHC can be used to test pressure and tempera-
ture switches. On board firmware provides the ability
to verify switch trip points, reset point and to test the
deadband of a pressure switch. To perform these type of
tests follow the procedures as outlined in the subsections
of Section 18.
The switch testing process incorporated in the HHC
firmware looks for a change of state that produces a
change of greater than either 2 volts or a 2 mA across
the corresponding miniature banana jacks. The banana
jacks are located on the bottom of the keypad on the
HHC. Prior to initiating these test procedures the
required electrical set up should be configured to provide
the necessary signal levels.
Section 18.1 Setting Up the HHC for Testing of
Pressure and Temperature Switches
The following procedure outlines the set up require-
ments for the test of pressure and temperature switches.
Step 1 With the HHC on and reading pressure or
temperature, in accordance with the type of switch to
be tested, press the Port Select key, designated PORT
SEL, the required number of times to leave activated the
Quick Select module being used for the test function and