Unihedron SQM-LU-DL-V, Operator'S Manual

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8.3 Calibration commands
8.3 Calibration commands
8.3.1 Calibration information request
The calibration information request “
cx
” returns all data about the specific light sensor in the unit required to calculate
a reading.
The format of the response is shown in table 8.9:
Table 8.9: Calibration information request response
Column Example value Description
0
c
Indicates that the calibration information is being returned.
2-13
00000017.60m
Light calibration offset in
mag
arcsec 2
.
15-26
0000000.000s
Dark calibration time period in seconds with millisecond resolution.
28-34
039.4C
Temperature in degrees C measured during light calibration.
Leading space for positive value.
Leading negative sign (-) for negative value.
36-47
00000008.71m
Offset of light sensor in
mag
arcsec
2
based on manufacturing reference.
The factory calibration light source is equivalent to 8.71
mag
arcsec
2
, and
when the “Light calibration” button is pressed in UDM, the meter
creates the light calibration offset value (17.60 in this case) so that
the meter reads 8.71 also.
49-55
039.4C
Temperature in degrees C measured during dark calibration.
Leading space for positive value.
Leading negative sign (-) for negative value.
56-57 Carriage return (0x0d), Line feed (0x0a).
An example of the response is:
c,00000017.60m,0000000.000s, 039.4C,00000008.71m, 039.4C
0123456789 123456789 123456789 123456789 123456789 1234567
8.3.2 Light calibration command
Calibration of the SQM-LU-DL-V is done at the factory in a controlled light and temperature environment.
Executing the Light calibration command “
zcalAx
” arms the light calibration mode.
A calibrated light source of approximately 13.5fc is supplied to the sensor.
The format of the response is shown in table 8.10:
Table 8.10: Light calibration response
Column Example value Description
0
z
Indicates that a “Calibration” response is being returned.
1
A
Indicates Light Calibration mode.
2
a
Indicates that the calibration is armed.
3
L
L = Locked; Wait for unlock before calibrating after Arm command,
firmware upgrades are disabled.
U = Unlocked; Calibrate immediately after Arm command, Enable
firmware upgrade.
Table continued on next page ...
Unihedron SQM-LU-DL-V Operator’s Manual -
20211013
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