Lake Shore 625, User Manual

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Lake Shore Model 625 Superconducting MPS User’s Manual
4-2 Operation
4.2.2 Magnet Field Display
The instrument can be setup to display calculated field. See Figure 4-2. This value is calculated using the output current
reading and the field constant. See Paragraph 4.13 to setup the field constant. If the instrument is setup to display in field,
then only the field reading will be displayed using the large 11
× 15 block characters. Other information is shown below
as well as to the right of the field reading. This includes the output field setting, the current ramp rate, the output current
reading, the output current setting, the output voltage reading, the compliance voltage limit, and the remote voltage sense
reading. Display setup is described in Paragraph 4.4.
Magnet Field
+8.50000
T
Set: +8.50000 T
Rate: 0.1000 A/s
Output I: +60.0000 A
Set: +60.0000 A
Output V: +0.1346 V
V Limit: 5.0000 V
V Sense: +0.0085 V
PSH On: 40 mA
Figure 4-2. Model 625 Magnet Field Display
4.2.3 Persistent Switch Heater Display
The lower right corner of the display shows the status of the persistent switch heater if the persistent switch is enabled. It
will indicate if the heater is off, on, warming, or cooling. If the heater is on, it will also display the heater current. This
area of the display will be blank if the persistent switch heater is disabled. Refer to Paragraph 4.14 for information on
setting up the Persistent Switch Heater Output.
4.2.4 LED Annunciators
There are five LED annunciators on the front panel that are used to indicate the status of the instrument. These are to
provide easy verification of the operation of the instrument.
Fault
On when a hardware fault condition exists, blinking when a soft fault condition exists.
Compliance On when output is in voltage compliance.
Ramping On when output current is ramping, blinking when ramp is paused.
PSH On
On when persistent switch heater is on, blinking when the heater is warming or cooling.
Remote
On when instrument is in remote computer interface mode.
4.3 KEYPAD DEFINITION
The Model 625 has 26 keys separated into 4 groups on the instrument front panel. The group of keys farthest to the left
control the persistent switch heater, the center group combines instrument setup and data entry, the keys farthest to the
right control the computer interface mode of the instrument, and the keys at the bottom control the output current.
4.3.1 Key Descriptions
Output Setting Sets the output current. Refer to Paragraph 4.5.
Ramp Rate
Sets the output current ramp rate. Refer to Paragraph 4.6.
Voltage Limit
Sets the compliance voltage limit for the output. Refer to Paragraph 4.7.
Zero Output Ramps the current to 0 A at the programmed ramp rate. Refer to Paragraph 4.8.
Stop Output Stops the output at the present value during a ramp. Refer to Paragraph 4.9.
Pause Output Pauses the output during a ramp. Press again to continue ramp. Refer to Paragraph 4.10.