Model 1835-C - Newport Corporation

Executing AUTO CAL with High Power (Thermopile) detectors:
1. With the detector connected to the 1835-C, remove the detector from the
radiation source and allow a minimum of 60 seconds for the detector
surface temperature to stabilize.
2. Press ENTER when AUTO CAL is displayed. The display message area will
display “ONE MOMENT”, followed by a buzzer sound indicating that AUTO
CAL is complete.
Executing AUTO CAL with Low Power (Photodiode) or Energy detectors:
Simply press ENTER when AUTO CAL is displayed. The display message area
will display “ONE MOMENT”, followed by a buzzer sound indicating that
AUTO CAL is complete. Low Power and Energy detectors do no have to be
connected to the 1835-C or removed from the radiation source to effectively
execute AUTO CAL.
2.4.5 User Calibration
The Model 1835-C allows one to create a detector responsivity which overrides
the responsivities obtained from the detector’s calibration module. This
allows one to account for the effects of additional optics and filters in the
measurement path.
When USR CAL is on, the USR CAL annunciator is lit and the meter adopts the
responsivity value displayed by the editable USR RESP value. Use the
PRESENT RESP function to display the current calibration module
responsivity.
The USR RESP units are the same as the PRESENT RESP units. Table 11 lists
the possible user calibration operations.
Table 11. User Calibration Operations
Menu Operation Keypad Commands Associated Remote Commands
USR CALIB ON, OFF Edit USR CALIB USRCAL, USRCAL?
ON, OFF
USR RESP Edit d.dddE±dd A/W * USRRESP, USERRESP?
PRESENT RESP ENTER to view RESP?
d.dddE±dd A/W *
*
Units of A/W, V/W or V/J may be displayed. These units are not editable.
2.4.6 DC Sampling
The Model 1835-C incorporates two analog-to-digital, (A/D) converters, one
with 20,000 count resolution and a second with 4096 count resolution. The
user may select which A/D will be used during DC CONT and DC SNGL acquisition
modes. All other modes use the 4096 count A/D. The 20,000 count A/D
converter, can operate at sample rates up to 25 Hz. The 4,096 count A/D
converter, can operate at sample rates up to 1000 Hz.
The SAMPLE PREC menu command, Table 12, selects which analog-to-digital
converter is used. Sampling frequency can be adjusted within the limits
imposed by the SAMPLE PREC state, see Table 13. When the SAMPLE PREC
state changes, the sampling frequency defaults to 25 Hz if the existing SAMPLE
FREQ is incompatible with the new SAMPLE PREC state.
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