Campbell HMP50, Instruction Manual

Page 1: ...HMP50 Temperature and Relative Humidity Probe Revision 10 09 C o p y r i g h t 1 9 9 5 2 0 0 9 C a m p b e l l S c i e n t i f i c I n c...

Page 2: ...ternational customers residing in countries served by Campbell Scientific Inc directly Affiliate companies handle repairs for customers within their territories Please visit www campbellsci com to det...

Page 3: ...ograms 6 5 1 Example for CR1000 7 5 2 Example for CR10X 8 6 Long Lead Lengths 9 7 Absolute Humidity 9 7 1 CR1000 Vapor Pressure Example 10 7 2 Sample CR10 X Program that Computes Vapor Pressure and Sa...

Page 4: ...nts ii Tables 1 Recommended Lead Lengths 1 2 Datalogger Connections 6 3 Calibration for Temperature 7 4 Calibration for Relative Humidity 7 5 Wiring for CR1000 and CR10X Examples 7 6 Wiring for Vapor...

Page 5: ...P50 TABLE 1 Recommended Lead Lengths 2 m Height Atop a tripod or tower via a 2 ft crossarm such as the CM202 Mast Leg CM202 CM6 CM10 CM110 CM115 CM120 UT10 UT20 UT30 9 11 11 14 14 19 24 14 24 37 Note...

Page 6: ...sor Sensor INTERCAP Relative Humidity Measurement Range 0 to 98 non condensing RH Output Signal Range 0 to 1 0 VDC Accuracy at 20 C 3 RH 0 to 90 Relative Humidity 5 RH 90 to 98 Relative Humidity Tempe...

Page 7: ...erature and relative humidity sensors 3 2 Mounting and Assembly Pull off the yellow shipping cap see Figure 1 The HMP50 must be housed inside a solar radiation shield when used in the field The 41303...

Page 8: ...HMP50 Temperature and Relative Humidity Probe Yellow Shipping Cap remove before installation FIGURE 1 HMP50 as Shipped FIGURE 2 HMP50 and 41303 5A Radiation Shield on a Tripod Mast 4...

Page 9: ...HMP50 Temperature and Relative Humidity Probe FIGURE 3 HMP50 and 41303 5A Radiation Shield on a CM202 Crossarm FIGURE 4 HMP50 and 41303 5A Radiation Shield Mounting Clamp 5...

Page 10: ...lue G G Power 12V Brown 12 V 12 V 12 V Shield Clear G 4 Wiring Connections to Campbell Scientific dataloggers are given in Table 2 The probe is measured by two single ended analog input channels one f...

Page 11: ...ABLE 3 Calibration for Temperature Units Multiplier degrees mV 1 Offset degrees Celsius 0 1 40 Fahrenheit 0 18 40 TABLE 4 Calibration for Relative Humidity Units Multiplier mV 1 Offset Percent 0 1 0 F...

Page 12: ...00 mV CR23X 1000 mV 21X CR7 5000 mV 3 3 SE Channel Black wire SE 3 Blue wire G 4 1 Loc T_C 5 1 Mult See Table 3 for alternate multipliers 6 40 Offset See Table 3 for alternate offsets Measure the HMP5...

Page 13: ...when it is powered The wire used in the HMP50 P N 18159 has resistance of 26 2 1000 feet Using Ohm s law the voltage drop Vd along the signal reference power ground lead is given by Eq 1 ft 1000 mV 2...

Page 14: ...elationship between relative humidity and air temperature finding the mean relative humidity is meaningless A more useful quantity is the mean vapor pressure The mean vapor pressure can be computed on...

Page 15: ...allTable Table1 NextScan EndProg 7 2 Sample CR10 X Program that Computes Vapor Pressure and Saturation Vapor Pressure Measure the HMP50 temperature 01 Volt SE P1 1 1 Reps 2 5 2500 mV Slow Range CR510...

Page 16: ...inimal maintenance Check monthly to make sure the radiation shield is free from debris The white screen at the tip of the probe should also be checked for contaminants When installed in close proximit...

Page 17: ...it To prevent scratching avoid touching the silver RH chip and handle the RH chip with care CAUTION 3 Rinse the RH chip or dispose of the old RH chip 4 Hold the sides of the rinsed or new chip and pl...

Page 18: ...HMP50 Temperature and Relative Humidity Probe 14...

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Page 20: ...a Corp CSC 11564 149th Street NW Edmonton Alberta T5M 1W7 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientific Centro Caribe S A CSCC 300 N Cementerio Edificio Breller Santo Doming...