User Manual

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