Hi
I would like to measure several PT-100 using 4WPB100 modules on the same excitation channel
I put the first 4WPB100 on DIF1, the PT-100 on DIF2, the second 4WPB100 on DIF3, the second PT-100 on DIF3 and so on.
In CRBasic:
Public Rs_R0(x), Temp(x)
BrHalf4W(Rs_R0,x,mV200,mV200,1,Vx1,x,2500,True,True,0,250,1.0,0)
PRTCalc (Temp,x,Rs_R0,0,1,0)
However, the first PT-100 is measured only
What would be the correct order of the 4WPB100 and the PT-100 on the DIF channels as well as the corresponding correct CRBasic commands for that?
Thank you very much in advance
stefan
Check out the manual for the 4WPB100: https://s.campbellsci.com/documents/us/manuals/4wpb100.pdf
Figure 3-1 provides a wiring diagram for each 4WPB100/PT-100 for the example program.
'Sensor 1
' VX1
' 1H: High side of PT
' 1L: Low side of PT
' 2H: Low side of PT
' 2L: Return of PT
' Ground: Return of PT
'Sensor 2
' VX2
' 3H: High side of PT
' 3L: Low side of PT
' 4H: Low side of PT
' 4L: Return of PT
' Ground: Return of PT
'Sensor 3
' VX3
' 5H: High side of PT
' 5L: Low side of PT
' 6H: Low side of PT
' 6L: Return of PT
' Ground: Return of PT
'Sensor 4
' VX4
' 7H: High side of PT
' 7L: Low side of PT
' 8H: Low side of PT
' 8L: Return of PT
' Ground: Return of PT
Public Rs_R0(4), Temp_C(4)
Const PTType=0
BeginProg
Scan (1,Sec,0,0)
'Example using a 4WPB100, assuming 4WPB100 resistor used
'exactly matches the resistance of the sensor at zero
'Celsius. If not, multiplier in BRHalf4W should be changed from 1.0
BrHalf4W(Rs_R0,4,mV1000,mV1000,1,Vx1,1,4000,True,True,0,250,1.0,0)
PRTCalc(Temp_C,4,Rs_R0,PTType,1,0)
NextScan
EndProg
Sam, thank you very much for your immediate reply and help!
Would it possible to excite all four sensors with the same excitation channel, e.g. Vx1, instead using for each sensor the four individual excitation channels Vx1-Vx4? What are the options if I have more than four sensors which need to be excited?