SRS Labs QMS 100 Series, Руководство пользователя

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4-6 Internal Error Detection in the SRS RGA
SRS QMS Gas Analyzer
checked at any time with the query command: ED?.
Several tests are performed during the check:
1. The ADC16 input is grounded and its digital output is measured to make sure it corresponds to
less than 15 mV.
2. A current of +5nA is injected into the electrometer and the output is read and compared to
expected values.
3. The same test is repeated with -5 nA of input current.
If an error is detected: Bit 5 of STATUS is set, DET_ERR is updated, and the Error LED is turned on.
The detector is reconfigured to its pre-check configuration once the tests are over.
Quadrupole Mass Filter RF P/S
STATUS Bit affected: 4
Error Byte affected: QMF_ERR
Error Reporting Command: EQ?
Error Codes prefix: RF
Power-on check?: Yes
The RF power supply that biases the rods of the Quadrupole Mass Filter is thoroughly checked upon a
power-on reset and can be tested at any time using the query command: EQ?.
The RF amplitude is set at the level corresponding to the maximum mass value for the head (100 amu
for RGA100, 200 amu for RGA200 and 300 amu for RGA300) and the following tests are done:
•
The voltage on the primary of the RF transformer is checked to make sure it is at least 2V lower
than the DC voltage used to power the instrument.
•
The amount of current flowing through the primary of the transformer is checked to make sure it
is less than 2.0 Amps.
•
RF_PRI is also checked (against RF_SET) to make sure the driver is not in current limiting
mode.
If a problem is detected in any of these checks Bit 4 of STATUS is set, QMF_ERR is updated, and the
Error LED is turned on.