Campbell Scientific 21XL 21X Micrologger - Page 66

sEcTloN 7. MEASUREMENT PROGRAMMING EXAMPLES Hl 1 3 (high and low sides of differentialchannel 1 LO1 and high side of 2). fil5 iLO5 Hi 6 EX1 COPPER CONSTANTAN FIGURE 7.4f1. Thermocouples with External Reference Junction The temper{ture of the 107 Probe is stored in input locatiof 1 and the thermocouple temperatureF in Locations 2-6. PROGRAM 01: 01: 02: 03: o4:05: 06: P1 1l 1l 1 11 1 1l ;l Temp 107 Probe Rep lN Chan Excite all reps w/EXchan 1 Loc [:REF TEMP ] Mult Offset 02: 01: 02: 03: 04: 05: 06: 07: 08: P1 4 5 2 1 1 1l 4 1l 0 Thermocouple Temp (DIFF) Reps 15 mV slow Range lN Chan Type T (Copper-Constantan) Ref Temp Loc REF TEMP Loc [:TC TEMP#1] Mult Offset 7.5 107 TEMPERATURE PROBE lnstruction 11 is designed to excite and measure the CampbQll Scientific 107 Thermistor Probe (or the ther(ristor portion of lhe 207 temperature and relative thumidity probe) and convert the measurement into temperature (oC). In this example, thf temperatures are obtained from three 107 p4obes. The measurements are made on single-erlded channels 1-3, and the temperaturqs are stored in input locations 1-3. CONNECTIONS The black lqads from the probes go to excitation channel 1, tfre white leads go to ground, and the red leads gq to single- ended channels 1, 2, and PROGRAM 01: P11 01: 3 02: 03: 04: 05: 06: Temp 107 Probe Reps lN Chan Excite all reps w/EXchan 1 Loc [:TEMP #1 ] Mult Offset 7.6 207 TEMPERATURE AND RH PROBE Instruction 12 excites and measures the RH portion of the Campbell Scientific 207 Temperature and Relative Humidity Probe. This instruction relies on a previously measured temperatu re for temperature compensation when computing RH. ln this example, three probes are measured. Instruction 11 is used to obtain the temperatures of the three probes which are stored in input locations 1-3; the RH values are stored in input locations 4-6. The temperature measurements are made on singleended input channels 1-3, just as in Example 7.5. The program listed below is a continuation of the program given in Example 7.5. CONNECTIONS The black leads from the probes are connected to excitation channel 1; the clear leads are connected to ground. The red leads are from the thermistor circuit and are connected to single- ended channels 1-3. The white leads are from the RH circuit and are connected to singleended channels 4-6. The correct order must be maintained when connecting the red and white leads; i.e., the red lead from the first probe is connected to single-ended channel 1 and the white lead from that probe is connected to single-ended channel 4, etc. 02: P12 01: 3 02: 4 000534::: 1 1 4 06: 07: 1 0 PROGRAM RH 207 Probe Reps lN Chan Excite all reps w/EXchan 1 Temperature Loc TEMP #1 Loc [:RH #1 ] Mult Offset 7-3