Campbell PC208 Instruction Manual

Measurements of Sap Flow by the Heat-Pulse Method. An Instruction Manual for the HPV system August, 1998 Steve Green HortResearch Institu

10 apple or kiwifruit, and so we have been able to use the same set of probes for periods of up to 3 months. In other species this may not be the cas

11 since the mass of air is negligible. The core sample is then immediately submerged in a beaker of water which has been placed on an accurate mass

12 in order to get the expression for the velocity profile as a function of stem radius, r [m]. This curve is then integrated over the sapwood cross-

13 output signals from the HPV unit should lie between ± 40 mV for the 1oC difference in temperature difference between the two sensors. The data log

14 3.2. Connecting the HPV unit to the data logger: There are two leads which must to be connected to the HPV unit - a signal lead and a power lead.

15 4. Installing the heat-pulse probes. This section gives advice on how to install the heat-pulse probes into a plant stem. Note: It is good prac

16 this is the downstream probe (unmarked) e.g. the highest probe in the stem orthe root probe nearest to the stem this is t

17 ELSE swear a lot blame someone else (but not me) goto deep_shit ENDIF Note1: if you cant find deep_shit, then your not

18 The following files have been supplied in the sub-directory A:\LOGGER of the installation disk: CR10-HP3.STN is the Station file required to comm

19 5.5. Retrieving data from the logger Use the program PC208 to retrieve all the ‘uncollected’ data from the data logger. 5.6. Operation of th

2 Summary Heat-pulse techniques can be used to measure sap flow in plant stems with minimal disruption to the sap stream (Swanson and Whitfield, 198

20 5.6.5. To find out the total running-time since the heat-pulse was fired (loc. 99) enter *6 99 A enter *0 to continue 5.6.6. To change t

21 1: 99 Loc [ _________ ] 4: Volts (SE) (P1) Measure current temp. signal and store in loc (21..32) 1: 12 Reps Change as requ

22 2: 30 Then Do 17: Do (P86) 1: 10 Set Output Flag High 18: Sample (P70) Ouput the date and time 1: 2 Reps 2: 91

23 2: 60 Mod/By 3: 93 Loc [ _________ ] 31: Z=X+Y (P33) 1: 92 X Loc [ _________ ] 2: 93 Y Loc [ _________ ] 3: 92

24 2: 3 >= 3: 2 F Change as required 4: 31 Exit Loop if True 45: End (P95) 46: Set Port(s) (P20) 1: 0 C8..C

25 The default time is 30 minutes 5.8.2. To fire a test heat-pulse enter *6 A D 1 (the lights should go on, and the program will run)

26 enter *1 15 A A A x A where x is max time in multiples of 0.1s default value if 500 s, i.e. x=500, but 300s might be OK 5.9. Listing o

27 16: End (P95) 17: If Flag/Port (P91) 1: 16 Do if Flag 6 is High 2: 30 Then Do 18: Do (P86) 1: 10 Set Output Flag High 1

28 2: 3 Port Number 45: Set Port (P20) 1: 1 Set High 2: 4 Port Number 46: Beginning of Loop (P87) 1: 1 Delay 2:

29 6. Running the ANALYSIS software ... (still under review) This section describes the software used to analyze the tz data collected by the data l

3 Contents Summary .. .. .. .. .. .. .. .. .. 2 1. Background and Theory .. .. .. .. .. .. 5 1.1 The origin of heat-pulse .. .. .. .. .. 5 1.2 Ide

30 prob_depth1: 0.50 1.20 2.20 3.50 prob_space1: 1.00 1.00 1.00 1.00 prob_depth2: 0.50 1.20 2.20 3.50 prob_sp

31 where opid = output identifier (103 ⇒ output from table 1, line 3) day = current day of year hrmin = time when heat-pulse was fire

32 For well-behaved velocity profiles (i.e. small curvature at large radii) all three methods yield similar results, but for profiles where the curva

33 * 32, 1.826, 0.879, 0.169, 0.0, * 36, 2.090, 0.818, 0.221, 0.0 / C-----------------------------------------------

34 c ... vfwood = volume fraction of wood = 0.34 c ... vfwat = volume fraction of water = 0.56 C---------------------------------------------------

35 ITOD = 1 IF(IDAY.GT.5) THEN IDAY = 1 TMIN = TMIN+5 TMAX = TMAX+5 CALL SETTEXTPOSITION(33 ,35,CURPOS) WRITE(*,*) &ap

36 SAPFLOWV(J,ITOD) = FLUXV(J) SAPFLOWF(J,ITOD) = FLUXF(J) c GOTO 299 C--------------------------------------

37 SX3 = SX3 - SX*SX2/N SXY = SXY - SX*SY/N SX2Y= SX2Y- SX2*SY/N SX2 = SX2 - SX*SX/N D = SX2*SX4 - SX3**2 A1 = (SX4*SXY - SX3*SX2Y)/D A2 =

38 DO 10 I=1,NLINE READ(NUNIT,99) LINE IF(OP) WRITE( *,99) LINE 10 CONTINUE 99 FORMAT(A75)

39 ENDIF IF(Y2LABEL) THEN CALL TITLEAXIS(1.15D0,0.5D0,YTITLEUNIT,1.4D0,1.4D0,NXPIX/1 & ,NYPIX,TALL,2) ! YAXIS TITLE CALL

4 5.8 Operation of the logger program - C21-HP4.DLD .. .. 24 5.9 Listing of the logger program - C10-HP4.CSI .. .. 25 6. Running the analysis

40 REAL*8 XX(NUM), YY(NUM) LOGICAL STATUS TYPE (WXYCOORD) WXY STATUS = SETCOLOR(LCOL) CALL MOVETO_W(XX(1), YY(1), WXY) DO 10 I=2,NUM STATUS

41 ELSE CALL NUMAXIS(XTICK+0.1,YTICK,YLABEL, XW,YH,NXPIX & , NYPIX,2, .FALSE.) !!!! NO LOG PLOT ON YAXIS ENDIF 10 CONTINUE R

42 C========================================================== IMPLICIT NONE REAL*8 HIGH, LOW, RANGE, DLHI, DLLO, DTICKS REAL

43 INTEGER I, NX REAL*8 X(NX), XMIN, XMAX XMIN = 1.0D10 XMAX = -1.0D10 DO 10 I=1,NX IF(X(I).LE.XMIN) XMIN = X(I) IF(X(I).GE.XMAX) XMAX =

44 7. References Barrett, D.J., Hatton, T.J., Ash, J.E., and Ball, M.C., 1995. Evaluation of the heat-pulse velocity technique for measurement of sa

45 Appendix A – use of an AM25T multiplexer: Listing of logger programme to connect 3 heat-pulse units to a single CR10 data logger. Note: One AM25T

46 1: 53 Set Port 3 Low 11: Volt (SE) (P1) 1: 2 Reps 2: 15 2500 mV Fast Range 3: 1 SE Channel 4: 31 -- Loc [

47 25: End (P95) 26: If Flag/Port (P91) ; Flag 6 is used to generate output 1: 16 Do if Flag 6 is High 2: 30 Then Do 27: Do (P86)

48 41: Z=X+Y (P33) ; Store the time (hrmin) (loc 92) 1: 92 X Loc [ _________ ] 2: 93 Y Loc [ _________ ] 3: 92 Z Loc [ _____

49 59: If Flag/Port (P91) 1: 12 Do if Flag 2 is High 2: 30 Then Do 60: Set Port(s) (P20) ; Port 1 (C1) is the heater control line

5 1. Background and Theory 1.1 The Origin of Heat-pulse Heat-pulse methods date back some 60 years to the work of Huber (1932) who first conceived

50 Appendix B – use of simple heat-pulse controller (no amplifiers) The heat-pulse controller and probes can be operated with most Campbell data log

51 4: 1 Type T (Copper-Constantan) 5: 100 Ref Temp (Deg. C) Loc [ _________ ] 6: 21 Loc [ _________ ] 7: 1 Mult 8: 0

52 19: Sample (P70) ! output the cross-over times 1: 8 Reps 2: 1 Loc [ _________ ] 20: Do (P86) 1: 26 Set Flag 6 Low 21:

53 34: End (P95) 35: Thermocouple Temp (SE) (P13) ! measure initial temp difference 1: 8 Reps 2: 1 2.5 mV Slow Range 3: 1

54 49: If (X<=>F) (P89) ! wait 10 s before making a Tz measure 1: 99 X Loc [ _________ ] 2: 3 >= 3: 10 F ! change

6 be inserted radially into the plant stem, with the temperature being measured at a point far enough below the surface of the stem to avoid the unkn

7 Figure 1. Arrangement of sensors within a plant stem for the compensation heat-pulse method.

8 probes, and by the disruption of xylem tissue associated with their placement. These perturbations produce a systematic underestimation in the meas

9 At this point, we note that a priori the wound size is not known, although we might expect it to be a little larger than the size of the drill hole