Simulate RTD or resistance
Simulate
1) Set up the Model 111 for RTD or Ohms and
temperature scale (°C or °F).
2) Disconnect the input wires from the device to be
calibrated or checked.
3) Connect the Model 111 to the device to be cali-
brated, being careful to observe proper connec-
tions for 2 or 3 Wire hookups.
4) Adjust the digital pot to the desired output value.
Output
Whenever SIMULATE mode is selected the word
SIM will appear on the LCD. SIM will flash when the
Model 111 is measuring the external excitation cur-
rent and will be steady when accurately simulating a
resistance. To change the output value, turn the
speed sensitive digital pot. Turning the pot slowly
will cause a gradual change in the output. A faster
change will occur when the pot is turned faster. A
filter circuit limits response when the pot is turned
too fast. This function operates in all three output
positions (HI, SET & LO).
Store
1) Switch to HI (or LO).
2) Turn the digital pot to desired value.
3) Press STORE. The LCD will flash once indicating
that the value has been stored
If a value is in the SET position and you want that
value in HI or LO, press and hold the STORE button
while moving the switch to HI or LO. The LCD will
flash once indicating that the value has been stored.
Release the STORE button. When there is no exci-
tation current or the current is less than 0.09 mA
SIM will flash on the LCD. “QUIK-CHEK” values
may be stored with SIM flashing.
Instantly recall temperatures
Any time you need a stored value just throw the
“QUIK-CHEK” switch. Any value in the RTD range
may be stored in HI & LO. The Model 111 remem-
bers the HI, LO and SET values for you with the
power on or off. The resolution of the stored value is
based on the excitation from the receiver. When
RTD type is selected after Ohms was selected 0°C
or 32°F is stored in all “QUIK-CHEK” positions.
When the ohms range is selected,100 will be the
setting for all “QUIK-CHEK” positions.
Note:
SIM constantly flashing on the LCD indicates that the excitation current is missing, out of range or is intermittent.
Check to see that the device being calibrated has operating power and that the 111 is properly connected. Also check the
manual for the device to make sure that the excitation current is in the range of 0.090 to 5.800 milliamps.
The Model 111
will simulate only with intstruments that use fixed excitation currents.
Some "smart" transmitters and scanning recorders or
indicators use intermittent (pulsed) currents to measure RTD's. Try putting recorders into a calibrate mode or lock them into
one channel. See Calibrating Additional Instruments on page one for more information.
Read an RTD sensor
Read
1) Set up the Model 111 for the RTD, Ohms and
temperature scale (°C or °F).
2) Disconnect the wires from the resistance sensor
to be read or checked.
3) Connect the Model 111 to the sensor to be
measured, being careful to observe proper con-
nections for 2 or 3 wire hookups.
4) Display present reading, Maximum or Minimum
temperature.
Input
Whenever READ mode is selected the word READ
will appear on the LCD. The Model 111 can mea-
sure temperatures in two ranges with resolution of
0.1° and 1°. The display is updated twice per
second to continuously track fast moving
temperatures. Using three wire hookups provides
accurate readings in long cable runs.
Add a jumper
approximately the
same gauge and
length as the wires
connected to the
111
3 Wire
Receiver
Hookup —
Simulate an
RTD or
resistance
2 Wire
Receiver
4 Wire
Receiver
Open RTDS
The Model 111 checks for open or high resistance
connections. Open or burned out RTDS are indicat-
ed by - - - - - on the display. Temperatures out of
range for the RTD selected will be indicated by
OVER and UNDER on the display.
MIN/MAX
To read the Maximum or Minimum temperature
since READ mode was entered, simply switch to
MAX or MIN. The value will appear on the LCD
along with the word MAX or MIN. The MAX/MIN
values are automatically updated and may be
viewed at any time without disturbing the other
values. Press RESET and the Model 111 will flash
the display once to indicate it has transfered the
present temperature into both MAX and MIN and
will update them as the measured temperature
changes.
3 Wire
RTD
3 Wire
Hookup
2 Wire
RTD
3 Wire Hookup
(Required)
4 Wire
RTD
3 Wire Hookup
(No 4th wire
connection to
111)
Hookup —
Read an RTD
or resistor
HI
SET
LO
MAX
READ
MIN
STORE
RESET
HI
SET
LO
MAX
READ
MIN
HI
SET
LO
MAX
READ
MIN
STORE
RESET
OFF
OUTPUT
OFF
READ
SIM
