Product manual

Model HC2S3 Temperature and Relative Humidity Probe

4: If (X<=>F) (P89)

1: 4 X Loc [ RH ]

2: 4 <

3: 103 F

4: 30 Then Do

5: Z=F x 10^n (P30)

1: 100 F

2: 0 n, Exponent of 10

3: 4 Z Loc [ RH ]

6: End (P95)

7: End (P95)

8: If time is (P92)

1: 0 Minutes (Seconds --) into a

2: 60 Interval (same units as above)

3: 10 Set Output Flag High (Flag 0)

9: Set Active Storage Area (P80)

1: 1 Final Storage Area 1

2: 101 Array ID

10: Real Time (P77)

1: 1220 Year,Day,Hour/Minute (midnight = 2400)

11: Average (P71)

1: 1 Reps

2: 3 Loc [ AirTC ]

12: Sample (P70)

1: 1 Reps

2: 4 Loc [ RH ]

6. Measuring Probes with Long Cables

For cable lengths longer than 6.1 m (20'), CSI recommends measuring the

voltage signals using differential inputs as discussed below. Connections for

differential inputs are given in Table 4-2.

The signal reference (yellow) and the power ground (gray) are in common

inside the HC2S3. When the HC2S3 temperature and relative humidity are

measured using a single-ended analog measurement, both the signal reference

and power ground are connected to ground at the datalogger. The signal

reference and power ground both serve as the return path for power. There

will be a voltage drop along those leads because the wire itself has resistance.

The HC2S3 draws approximately 2 mA when powered with 12V. The wire

used in the HC2S3 (P/N 27746) has resistance of 14.74 Ω/304.8 m (1000').

Since the signal reference and the power ground are both connected to ground

at the datalogger, the effective resistance of those wires together is half of

14.74 Ω/304.8 m (1000'), or 7.37 Ω/304.8 m (1000'). Using Ohm’s law, the