Lake Shore 234, User Manual

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Lake Shore Model 234/234D User’s Manual
Service 5-9
f. Repeat Steps c thru e for 1
Ω
, 10
Ω
, 100
Ω
, 10 k
Ω
, and 100 k
Ω
0.01% calibration resistors. For each resistor the RANGE switch to be
closed is shown in the table below. When all ranges have been
calibrated, the outputs should read as shown in the table below. Input
calibration is complete.
Output
Calibration Range ±1 mV
Resistor Switch Closed
1
Ω
RANGE 1 0 V
10
Ω
RANGE 2 1.6667 V
100
Ω
RANGE 3 3.3333 V
1 k
Ω
RANGE 4 5.0000 V
10 k
Ω
RANGE 5 6.6667 V
100 k
Ω
RANGE 6 8.3333 V
The output is 10 * log(Cal Resistor)/6.
5.4.4 Calibration Using Serial Interface Calibration Commands
Model 234 calibration consists of output calibration and input calibration.
NOTE: Allow about 30 minutes for the Model 234 Temperature Transmitter
to warm up before continuing with calibration.
1. Serial Interface Program
a. Connect the Serial Port of the computer to the transmitter via the
RJ11 connector.
b. Invoke QBASIC or QuickBasic.
c. Enter the Model 234 program provided in Paragraph 4.1.4.
d. Run the program.
e. Issue a command to verify the program is running. For example, the
*IDN? query to view the Model number and Software date.
2. Output calibration using the DA0 and DA20 Commands:
a. Connect the DVM negative lead to OUT–, and positive lead to OUT+.
Verify the 500
Ω
load resistor is also connected to OUT+ and OUT–
terminals.
b. Issue the DA0 serial interface command. Output should be close to
zero.