Campbell Scientific CR23X Micrologger - Manual (Page 142)

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-8
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Range code for
excitation
measurement (V
1
)
(Do not use autorange)
(Table 9-1)
03: 2 Range code for bridge
measurement (V
2
)
04: 2 Differential channel
number for first
measurement
05: 2 Excitation channel number
(Table 9-2A)
06: 4 Excitation voltage
(millivolts)
07: 4 Input location number
for first measurement
08: FP Multiplier
09: FP Offset
Input locations altered: 1 per repetition
*** 10 BATTERY VOLTAGE ***
FUNCTION
This instruction measures the CR23X input
voltage and writes it to an input location. The
units for voltage are volts. The measurement is
.2 to .3 volts less than actual battery voltage
measurement. See Section 14.2 for CR23X
power requirements.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 4 Input location
Input locations altered: 1
*** 11 107 THERMISTOR PROBE ***
FUNCTION
This Instruction applies a 2.5 VAC excitation
voltage to Campbell Scientific's Model 107
Thermistor Probe, makes a slow single-ended
voltage measurement across a resistor in series
with the thermistor, and calculates the
temperature in °C with a polynomial. A
multiplier of 1 and an offset of zero yields
temperature in degrees Celsius. The maximum
polynomial error from -40°C to +56°C is given
here:
Curve Fit Error --
Range (°C) Error (°C)
-40 to +56 <
±
1.0
-24 to +48 <
±
0.1
TABLE 9-3. Excitation/Integration Codes
Code Result
0x excite all rep with channel x
1x increment chan x with each rep
2x excite all reps with channel x, slow 60 Hz
rejection, 10 ms delay
3x excite all reps with channel x, slow 50 Hz
rejection, 10 ms delay
4x increment chan x with each rep, slow 60 Hz
rejection, 10 ms delay
5x increment chan x with each rep, slow 50 Hz
rejection, 10 ms delay
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Single-ended channel
number of first
measurement
03: 2 Excitation channel/
Integration (Table 9-3)
04: 4 Input location for first
measurement
05: FP Multiplier
06: FP Offset
Input locations altered: 1 per repetition
*** 12 207 RELATIVE HUMIDITY PROBE ***
FUNCTION
This instruction applies a 3.0 VAC excitation
across Campbell Scientific's Model 207
Temperature and RH Probe, makes a fast
single-ended measurement across a series
resistor, calculates the result with a 5th order
polynomial, and performs the required
temperature compensation before outputting
the result in % RH.
When measuring several probes, all the RH
elements should be connected sequentially.
The temperature values used to correct the RH
measurements should also be stored
sequentially to make use of the REP feature in
Instruction 11.