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4.5.4 Returning to
Room Temperature
Follow this procedure to return the probe station to room temperature and to
prepare the station for sample exchange.
1. Use the z-axis micrometers to raise all probes up 3 mm to 4 mm above the sam-
ple stage.
2. Press the
CCR off
button.
The main power switch may be left on.
3. Warm the sample stage by entering a setpoint of 290 K and entering the appro-
priate controller settings given in TABLE 4-5.
4. Warm the radiation shield, CCR second stage, and CCR first stage by entering a
setpoint of 290 K and entering the appropriate controller settings given in
TABLE 4-5.
5. Purge and open the vacuum chamber when all stages are at their temperature
setpoints and the probe arm is above 290 K .
6. If the probe station is going to be out of service for any length of time perform
these procedures:
a. If the vacuum chamber was opened, reinstall the radiation shield lid and
vacuum chamber lid.
b. Close the purge valve and disconnect the gas line.
c.
Open the vacuum isolation valve.
d. Turn on the turbo pump for approximately 15 min.
e. Close the vacuum isolation valve.
f.
Turn off and vent the turbo vacuum pump (section 4.4.3).
4.5.5 Temperature
Control Summary
The temperature controller configuration table (TABLE 4-2) and the CCR and
electronic control settings table (TABLE 4-4 and TABLE 4-5) summarize the typical
settings needed to maintain the Model CRX-6.5K temperature control. TABLE 4-5
provides the sample stage electronic control settings.
Temperature
controller
Input
Sensor type*
Filter
Temperature
limit**
Input units
Sensor curve
Sample stage
Model 336
temperature
controller
A
Calibrated silicon
diode
On
(8 pts 10%
window)
360 K
Kelvin
User curve 21
Radiation shield
B
Silicon diode
DT-670
Probe arm
C
CCR second stage
D
325 K
CCR first stage
Not monitored
—
—
—
—
* Range for silicon diodes is 2.5 V with diode current 10μA.
** Controller maximum temperature limit set above operational maximum to avoid nuisance system shutdown during operation.
TABLE 4-2
Model 336 temperature controller input settings
Output
Control input
Output
mode
Heater
resistance
Max current
Power up
enable
Heater out
display
Setpoint
ramping
Heater range
1
Input A
(sample stage)
Closed loop
PID
25
Ω
2 A
(for 100 W)
Off
Power
Off
Low-High
2
Input B
(radiation shield
stage)
1.414 A
(for 50 W)
High
TABLE 4-3
Model 336 temperature controller output settings
