Campbell CR800 Series - Example: 100 Ω PRT in Three-Wire Half Bridge with Voltage Excitation (PT100; Brhalf3 W() )

Section 7. Installation
266
arise from variances in the 0.01% range translation resistors internal to the
CR800.
7.7.16.4 Example: 100 Ω PRT in Three-Wire Half Bridge with Voltage
Excitation (PT100 / BrHalf3W() )
FIGURE 66: PT100 BrHalf3W() Three-Wire Half-Bridge Schematic
Procedure Information
BrHalf3W() Three-Wire Half-Bridge Equations
X = RS / Rf
RS = Rf • X
VX = VS/(RS/(Rf + RS))
Bridge Resistor Values (mΩ)
Rf
100000
Procedure
1. Build circuit
1
:
a. Use FIGURE: PT100 BrHalf3W() Three-Wire Half-Bridge Schematic
(p.
266)
as a template.
b. For Rf, choose a 1%, 10 ppm/°C, 10000000 mΩ (10 kΩ resistor).
2. Wire circuit to datalogger:
Use FIGURE: PT100 BrHalf3W() Three-Wire Half-Bridge Schematic
(p. 266)
as the wiring diagram.