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B-1 

Appendix B.  Example Program 

The nominal calibration sensitivity is 67.1 

µ

V/W

–2

 for the HFP01#1 and  

67.0 

µ

V/W

–2

 for the HFP01#2. In CRBasic Example 

B-1

, the nominal 

calibration sensitivity is 67.1 

µ

V/W

–2

TABLE B-1.  Wiring for CRBasic Example B-1 

Description 

Color  CR3000 

Sensor Signal #1 

White 

7H 

Sensor Signal Reference #1 

Green 

7L 

Shield #1 

Clear 

 

Sensor Signal #2 

White 

8H 

Sensor Signal Reference #2 

Green 

8L 

Shield #2 

Clear 

 

 

CRBasic Example B-1.  Sample CR3000 Program using Differential Measurement Instructions 

'CR3000 Series Data Logger 
 
'This data logger program measures two HFP01 Hukseflux soil heat flux sensors 
 
'*** Constants *** 

Const

  HFP01_CAL_1 = 14.90  

'Unique multiplier for HFP01 #1. 1000/sensitivity (1000/67.1)

 

Const

  HFP01_CAL_2 = 14.92  

'Unique multiplier for HFP01 #2. 1000/sensitivity (1000/67.0)

 

 

'*** Energy balance sensor variables *** 

 

Public

 shf(2) 

Dim

 shf_cal(2)  

'Soil heat flux plate calibration coefficients. 

Units

 shf = W/m^2 

 

'*** Final Output Data Tables *** 

 

DataTable

 (soil_hf,TRUE,-1) 

  

DataInterval

 (0,30,Min,10) 

  

Average

 (2,shf(1),IEEE4,FALSE) 

EndTable 

 

'*** Program *** 

 

BeginProg 

   

'Load the HFP01 factory calibration. 

  shf_cal(1) = HFP01_CAL_1 
  shf_cal(2) = HFP01_CAL_2 
 
  

Scan

 (1,Sec,3,0) 

   

    'Measure the HFP01 soil heat flux plates. 

    

VoltDiff

 (shf(1),2,mV50C,7,TRUE,200,250,shf_cal(),0) 

 
    

CallTable

 soil_hf 

     
  

NextScan 

EndProg 

 

Summary of Contents for HFP01

Page 1: ...HFP01 Soil Heat Flux Plate Revision 1 20 Copyright 2002 2020 Campbell Scientific Inc...

Page 2: ...ucts to CSI CSI will return such Products by surface carrier prepaid within the continental United States of America To all other locations CSI will return such Products best way CIP port of entry per...

Page 3: ...ing address is CAMPBELL SCIENTIFIC INC RMA _____ 815 West 1800 North Logan Utah 84321 1784 For all returns the customer must fill out a Statement of Product Cleanliness and Decontamination form and co...

Page 4: ...beginning work Wear a hardhat and eye protection and take other appropriate safety precautions while working on or around tripods and towers Do not climb tripods or towers at any time and prohibit cl...

Page 5: ...spection 1 4 QuickStart 1 5 Overview 3 6 Specifications 4 7 Installation 4 7 1 Placement in Soil 5 7 2 Wiring 6 7 3 Programming 7 7 4 Soil Heat Flux and Storage 7 8 Maintenance 8 9 References 8 Append...

Page 6: ...1 General characteristics of a heat flux sensor C 1 C 2 Deflection error C 2 Tables 7 1 Wire Color Function and Data Logger Connections 6 B 1 Wiring for CRBasic Example B 1 B 1 CRBasic Example B 1 Sa...

Page 7: ...is rugged it should be handled as a precision scientific instrument 3 Initial Inspection Upon receipt of the HFP01 inspect the packaging and contents for damage File damage claims with the shipping co...

Page 8: ...ate the sensor in the select Sensors Soil folder Double click HFP01 Soil Heat Flux Plate Type the sensitivity provided on the calibration sheet this value is sensor specific 4 Click the Wiring tab to...

Page 9: ...splay in LoggerNet RTDAQ PC400 or PC200W to make sure it is making reasonable measurements 5 Overview The HFP01 Soil Heat Flux Plate uses a thermopile to measure temperature gradients across its plate...

Page 10: ...s and principles of operation of heat flux sensors is shown in Appendix C General Theory of Heat Flux Sensors p C 1 Features Ideal for energy balance or Bowen ratio systems Compatible with Campbell Sc...

Page 11: ...ors are installed in the undisturbed face of the hole Measure the sensor depths from the top of the hole With a small knife make a horizontal cut 16 cm below the surface into the undisturbed face of t...

Page 12: ...ABLE 7 1 Wire Color Function and Data Logger Connections Wire Color Wire Function Data Logger Single Ended Measurement Data Logger Differential Measurement White Signal U configured for single ended a...

Page 13: ...ded at www campbellsci com old manuals The HFP01 is measured using either a single ended VoltSE or differential VoltDiff instruction The differential measurement is recommended Syntax of the VoltDiff...

Page 14: ...at capacity of dry soil is a reasonable value for most mineral soils Hanks and Ashcroft 1980 The storage term is then given by Eq 3 and the soil heat flux at the surface is given by Eq 4 S T C d t s s...

Page 15: ...can now be edited for additional refinement Once the file is edited with CRBasic Editor Short Cut can no longer be used to edit the program it created 2 To add the Short Cut wiring information into t...

Page 16: ...ogger This data logger program measures two HFP01 Hukseflux soil heat flux sensors Constants Const HFP01_CAL_1 14 90 Unique multiplier for HFP01 1 1000 sensitivity 1000 67 1 Const HFP01_CAL_2 14 92 Un...

Page 17: ...will enhance the output signal In FIGURE C 1 the joints of a copper constantan thermopile are alternatively placed on the hot and the cold side of the sensor The thermopile is embedded in a filling ma...

Page 18: ...nd its environment for example 0 6 for a typical sensor and 0 03 for an insulating wall is about 40 FIGURE C 2 Deflection error The heat flux is deflected at the edges of the sensor As a result the he...

Page 19: ...cennes France Phone 0033 0 1 56 45 15 20 Email info campbellsci fr Website www campbellsci fr Germany Location Bremen Germany Phone 49 0 421 460974 0 Email info campbellsci de Website www campbellsci...

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