Campbell KH20 Bedienerhandbuch

INSTRUCTION MANUALEddy Covariance SystemCA27 and KH20Revision: 7/98Copyright (c) 1994-1998Campbell Scientific, Inc.

SECTION 2. STATION INSTALLATION2-22.1 SENSOR HEIGHTThe eddy covariance sensors must be mountedat some height that ensures that themeasurements are b

SECTION 2. STATION INSTALLATION2-3FIGURE 2.2-2 CA27, KH20, HMP35C, and Wind Sentry Set On a CM6 Tripod2.3 KH20 CALIBRATIONSEach KH20 is calibrated

SECTION 2. STATION INSTALLATION2-4TABLE 2.4-1 Polynomial Coefficientsa0 = 6984.505294a1 = -188.9039310a2 = 2.133357675a3 = -1.288580973 x 10-2a4 = 4.

SECTION 2. STATION INSTALLATION2-5The sensors are installed in the undisturbedface of the hole. Measure the sensor depthsfrom the top of the hole.

SECTION 2. STATION INSTALLATION2-6TABLE 2.6-1. CA27 and KH20 Sensor LeadColor AssignmentsSensor ColorCA27 Wind + GreenCA27 Wind - BlackCA27 Shield C

SECTION 2. STATION INSTALLATION2-7Be sure the 21X has a good earth ground, toprotect against primary and secondary lightningstrikes. The purpose of

3-1SECTION 3. SAMPLE 21X PROGRAMThis section provides a sample program that may be used to measure the eddy covariance sensors andthe auxiliary senso

SECTION 3. SAMPLE 21X PROGRAM3-2;05: Z=X (P31)1: 3 X Loc [ lnVh ]2: 4 Z Loc [ Vh ];Copy KH20 output.;06: Z=X (P31)1: 3 X Loc [ lnVh

SECTION 3. SAMPLE 21X PROGRAM3-313: If Flag/Port (P91)1: 10 Do if Output Flag is High (Flag 0)2: 30 Then Do;(w'T')rhoCp = H;14: Z=X*Y (P36)

Warranty and AssistanceThe CA27 AND KH20 are warranted by CAMPBELL SCIENTIFIC, INC. tobe free from defects in materials and workmanship under normal u

SECTION 3. SAMPLE 21X PROGRAM3-423: Set Active Storage Area (P80)1: 1 Final Storage2: 12 Array ID24: Resolution (P78)1: 0 low resolution25: Real Time

SECTION 3. SAMPLE 21X PROGRAM3-505: Z=X*Y (P36)1: 42 X Loc [ e ]2: 48 Y Loc [ RH_frac ]3: 42 Z Loc [ e ]06: Volts (SE) (P1)1: 2 Rep

SECTION 3. SAMPLE 21X PROGRAM3-615: Pulse (P3)1: 1 Reps2: 1 Pulse Input Chan3: 21 Low Level AC, Output Hz4: 49 Loc [ WndSpd ]5: .75 Mult6: .2 Offs

SECTION 3. SAMPLE 21X PROGRAM3-724: Do (P86)1: 42 Set Port 2 High;Measure CS615 soil moisture probe.;When the CS615 is off (Flag 4 low),;Input Locati

SECTION 3. SAMPLE 21X PROGRAM3-835: Average (P71)1: 1 Reps2: 46 Loc [ Tsoil ]36: If Flag/Port (P91)1: 10 Do if Output Flag is High (Flag 0)2: 30

SECTION 3. SAMPLE 21X PROGRAM3-945: If Flag/Port (P91)1: 10 Do if Output Flag is High (Flag 0)2: 10 Set Output Flag High46: Set Active Storage Area (

SECTION 3. SAMPLE 21X PROGRAM3-1005: Z=F (P30)1: 1010 F2: 27 Z Loc [ rhoCp ]06: Z=F (P30)1: 2440 F2: 28 Z Loc [ Lv ];Measure constant for

SECTION 3. SAMPLE 21X PROGRAM3-1119: Internal Temperature (P17)1: 40 Loc [ RefTemp ];Prev_Ts for first pass.;20: Thermocouple Temp (DIFF) (P14)1: 1

SECTION 3. SAMPLE 21X PROGRAM3-1230: End (P95)31: Beginning of Subroutine (P85)1: 5 Subroutine 532: Z=X*F (P37)1: 49 X Loc [ WndSpd ]2: .00174 F3:

SECTION 3. SAMPLE 21X PROGRAM3-13TABLE 3.1-1. Output from Example Eddy Covariance Program01: ID = 11; compile time and constants02: DAY03: Time(hhmm

iEDDY COVARIANCE SYSTEMTABLE OF CONTENTSPDF viewers note: These page numbers refer to the printed version of this document. Usethe Adobe Acrobat® bo

4-1SECTION 4. CALCULATING FLUXES USING SPLITSPLIT (PC208E software) can be used to apply the air density and oxygen corrections to the measuredsurfac

SECTION 4. CALCULATING FLUXES USING SPLIT4-2column # 7: Lv oldcolumn # 8: avg wcolumn # 9: avg Tcolumn # 10: avg InVcolumn # 11: avg Vhcolumn # 12: s

5-1SECTION 5. TROUBLESHOOTINGThis section offers some solutions to common problems. All the locations and data values are based onthe example progra

A-1APPENDIX A. USING A KRYPTON HYGROMETER TO MAKEWATER VAPOR MEASUREMENTSA.1 WATER VAPOR FLUXESThe krypton lamp used in the hygrometer emitsa major

APPENDIX A. KRYPTON HYGROMETER IN WATER VAPOR MEASUREMENTSA-2()LE LwInVxkOCvhw=′′−+1(9)Where OC1 is defined by Eq. (10).()OC LkkCMPRwTvowoo11=−′′−(10

APPENDIX A. KRYPTON HYGROMETER IN WATER VAPOR MEASUREMENTSA-3where T is in Kelvin. Directly substitute Eq.(19) into (16) and ignore the last term wi

B-1APPENDIX B. REMOVING THE TRANSDUCERS ON THE CA27Firmly hold the transducer, while loosening the knurled knob. Once the knob is loosened, gently p

This is a blank page.

C-1APPENDIX C. ADJUSTING THE CA27 ZERO OFFSETA zero velocity anechoic chamber can be made by lining a 5-gallon bucket with foam. The foam liningprev

D-1APPENDIX D. LIST OF VARIABLES AND CONSTANTSρ′vg m-3Instantaneous deviation of water vapor density from meanρag m-3Density of moist airρog m-3Densi

E-1APPENDIX E. REFERENCESBrutsaert, W.: 1982, Evaporation into theAtmosphere, D. Reidel Publishing Co.,Dordrecht, Holland, 300.Buck, A. L.: 1976, “

This is a blank page.

Campbell Scientific CompaniesCampbell Scientific, Inc. (CSI)815 West 1800 NorthLogan, Utah 84321UNITED [email protected]

1-1SECTION 1. SYSTEM OVERVIEW1.1 REVIEW OF THEORYThe surface layer (Figure 1.1-1) is comprised ofapproximately the lower 10% of the atmosphericbound

SECTION 1. SYSTEM OVERVIEW1-2Wind direction must also be measured. Thewind direction is used to identify periods whenthe mean wind was blowing over

SECTION 1. SYSTEM OVERVIEW1-31.3.3 NO ABSOLUTE REFERENCEThe CA27 zero offset drifts with ambient airtemperature. The zero offset drift does noteffe

2-1SECTION 2. STATION INSTALLATIONFigure 2-1 depicts a typical eddy covariance station that measures the latent and sensible heat flux,ambient air te