Campbell CR800 Series User Manual

Section 7. Installation
274
'Calculate X2
X2 = (X1/1000) + (R2/(R1+R2)
'Calculate RS and RS_RS0
RS = (R4*X2) / (1-X2)
RS_RS0 = RS/RS0
....'Calculate temperature from RS_RS0:
'PRTCalc(Dest,Reps,Source,PRTType,Mult,Offset)
PRTCalc(DegC,1,RS_RS0,1,1.0,0)
NextScan
EndProg
Notes
The following relationships are used in, or are related to, the previous procedure.
Maximum Excitation Voltage
Used:
V1
@maxT
= maximum voltage in the CR800 analog voltage input range
VX
MAX
= V1
@maxT
/((R3
@maxT
/(R3
@maxT
+R4)) – (R2/(R1+R2)))
Related:
V1
@maxT
= VX*((R3
@maxT
/(R3
@maxT
+R4)) – (R2/(R1+R2)))
Calibrate PRT
Used:
X
CAL
= (1000*(V1
CAL
/VX)), where (1000*(V1
CAL
/VX)) is the output of
BrFull() with Mult = 1, Offset = 0
X3
CAL
= (X
CAL
*0.001) + (R2/(R1+R2))
Related:
V1
CAL
= VX*((R3
CAL
/(R3
CAL
+R4)) – (R2/(R1+R2)))
Slope, Offset, and Xp
M = 0.001
B = (R2/(R1+R2))
Xp = ((1000*(V1/VX))*M+B

Campbell CR800 Series Specifications

General

Brand	Campbell
Model	CR800 Series
Category	Data Loggers
Language	English