Campbell Scientific 223-L Delmhorst Cylindrical Soil Moisture Block User Manual
Page 25
223 Delmhorst Cylindrical Soil Moisture Block
05: AC Half Bridge (P5)
;Measure the 2 connected 223 blocks
1:
2
Reps
2:
14
500 mV Fast Range
3:
1
SE
Channel
4:
2
Excite all reps w/Exchan 2
5:
500
mV
Excitation
6:
1--
Loc [ BlockR_1 ]
; -- >>> advance location by index
7:
1.0
Mult
8:
0.0
Offset
06: BR Transform Rf[X/(1–X)] (P59)
;Calculate resistance from Vs/Vx
1:
2
Reps
2:
1--
Loc [ BlockR_1 ]
3:
1.0
Mult
(Rf)
07: End (P95)
08:
Set Port (P20)
;Turn off AM416
1:
0
Set
Low
2:
1
Port
Number
;The following loop checks each block resistance and calculates
;water potential if BlockR < 17 kohms. Because 2 blocks are measured
;with each pass through the previous measurement loop, it is simpler
;to use a separate loop for the calculations.
;Leave out following loop if only recording block resistance.
09: Beginning of Loop (P87)
;Loop to calculate water potential
1:
0
Delay
2:
32
Loop
Count
10: If (X<=>F) (P89)
;If Rs < 17, apply polynomial
1:
1--
X Loc [ BlockR_1 ]
2:
4
<
3:
17
F
4:
30
Then
Do
11: Z=X*F (P37)
;Scale Rs for polynomial
1:
1--
X Loc [ BlockR_1 ]
2:
.1
F
3:
33--
Z Loc [ WatPo_1 ]
12: Polynomial (P55)
;Convert Rs to bars with 10 bar polynomial
1:
1
Reps
2:
33--
X Loc [ WatPo_1 ]
3:
33--
F(X) Loc [ WatPo_1 ]
4:
.15836 C0
5:
6.1445 C1
6:
–8.4198 C2
7:
9.2493 C3
8:
–3.1685 C4
9:
.33392 C5
13: Else (P94)
;If Rs > 17 load overrange value for potential
19