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Campbell HMP45C Instruction Manual - Warranty and Assistance

Manual is about: Temperature and Relative Humidity Probe

Summary of HMP45C

  • Page 1

    Instruction manual model hmp45c temperature and relative humidity probe revision: 2/07 copyright © 1990 - 2007 campbell scientific australia pty ltd.

  • Page 2: Warranty and Assistance

    Warranty and assistance the model hmp45c temperature and relative humidity probe is warranted by campbell scientific australia pty ltd. To be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless specified otherwise. Batteries...

  • Page 3: Hmp45C Table of Contents

    Hmp45c table of contents pdf viewers note: these page numbers refer to the printed version of this document. Use the adobe acrobat® bookmarks tab for links to specific sections. 1. General description ...............................1 2. Specifications …......................................2 2.1 tem...

  • Page 4: Model Hmp45C Temperature and

    Model hmp45c temperature and relative humidity probe (1) general description the hmp45c temperature and relative humidity probe contains a platinum resistance temperature detector (prt) and a vaisala humicap ® 180 capacitive relative humidity sensor. The -l option on the model hmp45c temperature and...

  • Page 5: 2. Specifications

    Model hmp45c temperature and relative humidity probe 2. Specifications operating temperature: -40°c to +60°c storage temperature: -40°c to +80°c probe length: 25.4 cm (10 in.) probe body diameter: 2.5 cm (1 in.) filter: 0.2 μm teflon membrane filter diameter: 1.9 cm (0.75 in.) power consumption: sup...

  • Page 6: 3. Installation

    Model hmp45c temperature and relative humidity probe 3. Installation 3.1 siting sensors should be located over an open level area at least 9 m (epa) in diameter. The surface should be covered by short grass, or where grass does not grow, the natural earth surface. Sensors should be located at a dist...

  • Page 7

    Model hmp45c temperature and relative humidity probe figure 3-1. Hmp45c and 41003-5 radiation shield on a tripod mast figure 3-2. Hmp45c and 41003-5 radiation shield on a cm200 series crossarm 4 cm200 series crossarm 41003-5 split nut u-bolt.

  • Page 8: 4. Wiring

    Model hmp45c temperature and relative humidity probe 4. Wiring connections to campbell scientific dataloggers are given in tables 4-1 through 4-3. The probe can be measured by two single-ended or differential analog input channels. When measuring the hmp45c with single-ended measurements, the purple...

  • Page 9: 5. Example Programs

    Model hmp45c temperature and relative humidity probe 5. Example programs this section is for users who write their own datalogger programs. A datalogger program to measure this sensor can be created using campbell scientific’s short cut program builder software. You do not need to read this section ...

  • Page 10

    Table 5-2 calibration for relative humidity units multiplier (% mv -1 ) offset (%) celsius 0.1 0 fahrenheit 0.001 0 model hmp45c temperature and relative humidity probe the hmp45c output scale is 0 to 1000 millivolts for the temperature range of -40°c to +60°c and for the relative humidity range of ...

  • Page 11

    Model hmp45c temperature and relative humidity probe cr1000 program using single-ended measurement instructions using 12v on datalogger 'cr1000 program to measure hmp45c with single-ended measurements public airtc public rh datatable(temp_rh,true,-1) datainterval(0,60,min,0) average(1,airtc,ieee4,0)...

  • Page 12: 6. Long Lead Lengths

    Model hmp45c temperature and relative humidity probe ;measure the hmp45c temperature. ; 03: volt (se) (p1) 1: 1 reps 2: 5 2500 mv slow range ;cr510, cr500 (2500mv); cr23x (1000 mv); 21x, cr7 (5000 mv) 3: 3 se channel ;yellow wire (se 3), white or purple wire (ag) 4: 1 loc [ t_c ] 5: .1 mult ;see tab...

  • Page 13

    Model hmp45c temperature and relative humidity probe at the datalogger, the effective resistance of those wires together is half of 27.7 Ω/1000 feet, or 13.9 Ω/1000 feet. Using ohm’s law, the voltage drop (v d ), along the signal reference/power ground, is given by eq. (1). V d = i ∗ r = 4 ma ∗ 13.9...

  • Page 14

    Model hmp45c temperature and relative humidity probe cr10(x) program using differential measurement instructions using 12v on datalogger ;turn the hmp45c on. ; 01: do (p86) 1: 41 set port 1 high ;orange wire (c1) ;pause 150 msec before making measurements so the ;probe can stabilize on true readings...

  • Page 15: 7. Absolute Humidity

    Model hmp45c temperature and relative humidity probe 7. Absolute humidity the hmp45c measures the relative humidity. Relative humidity is defined by the equation below: 100 e e rh s ∗ = (2) where rh is the relative humidity, e is the vapor pressure in kpa , and e s is the saturation vapor pressure i...

  • Page 16

    Model hmp45c temperature and relative humidity probe cr1000 program that computes vapor pressure and saturation vapor pressure 'cr1000 program that calculates vapor pressure public airtc public rh public rh_frac, e_sat, e_kpa datatable(temp_rh,true,-1) datainterval(0,60,min,0) average(1,airtc,ieee4,...

  • Page 17: 8. Sensor Maintenance

    Model hmp45c temperature and relative humidity probe ;measure the hmp45c relative humidity. ; 04: volt (se) (p1) 1: 1 reps 2: 5 2500 mv slow range ;cr510, cr500 (2500mv); cr23x (1000 mv); 21x, cr7 (5000 mv) 3: 4 se channel ;blue wire (se 4), white or purple wire (ag) 4: 2 loc [ rh_frac ] 5: .001 mul...

  • Page 18

    Model hmp45c temperature and relative humidity probe recalibrate the hmp45c annually. Obtain an rma number before returning the hmp45c to campbell scientific for recalibration. 9. Troubleshooting symptom: -9999, nan, -40 deg c, or 0 % relative humidity 1. Check that the sensor is wired to the correc...