Unihedron SQM-LU-DL, Operator'S Manual

Page: 18 / 101

4 Specifications
4 Specifications
USB connection USB B connector.
5m USB A to USB B cable supplied.
USB FTDI VCP driver, serial port emulator at 115200baud.
Physical Size 5.5” x 2.6” x 1.1”
Meter weight 110g
Battery pack with batteries weight 160g
USB cable weight 140g
Meter precision Each SQM-LU-DL is factory-calibrated. The absolute precision of each meter
is believed to be
±
10% (
±
0.10 mag/arcsec
2
). The difference in zero-point
between each calibrated meter is typically
±
10% (
±
0.10 mag/arcsec
2
)
Field of View The Half Width Half Maximum (HWHM) of the angular sensitivity is
≈
10.
The Full Width Half Maximum (FWHM) is then
≈
20. The sensitivity to a
point source
≈
19 off-axis is a factor of 10 lower than on-axis. A point source
≈
20 and
≈
40 off-axis would register 3.0 and 5.0 magnitudes fainter,
respectively.
Power requirement 18mA (from the 5V USB connection). Can be put to sleep and woken up
for battery operated data logging.
3.42V minimum under battery operation.
The included battery adapter can handle up to 30VDC.
Operating temperature range -40
°
C to 85
°
C
Temperature sensor Accuracy:
±
2
°
C maximum at 25
°
C
Location: Internal near light sensor, measures internal meter temperature for
light sensor value compensation.
Temperature update rate 4.3 seconds, 256 samples taken at 60Hz then averaged.
Data logging capacity Latest model (Extended memory version): 1048576 records total.
Initial model (1MB Flash chip, 32 bytes per record): 32768 records total.
Second generation model (16 bytes per record): 65536 records total.
For actual memory capacity; see back label (no entry = 32768 records) or
UDM datalogger page while connected to the meter.
Real Time Clock accuracy +1.73s/day @25
°
C, -2.27s/day @50
°
C, per Citizen crystal
CFS206-32.768KDZB-UB
18
Unihedron SQM-LU-DL Operator’s Manual -
20220119