Campbell CR800 Series, Operator'S Manual

Page: 262 / 598

Section 7. Installation
262
Excitation Ranges
CR6 CR800/CR1000 CR3000
±
2500 mV
±
2500 mV
±
5000 mV
± 2.000 mA
n/a
± 2.500 mA
7.7.16.3 Example: 100 Ω PRT in Four -Wire Half Bridge with Voltage
Excitation (PT100 / BrHalf4W() )
FIGURE 65: PT100 BrHalf4W() Four-Wire Half-Bridge Schematic
Procedure Data
BrHalf4W() Four-Wire Half-Bridge Equations
X = RS / Rf
RS = Rf • X
VX = (VS • (Rf + RS + R1) / RS)
Bridge Resistor Values (mΩ)
R1 Rf
10000000 100000
Procedure
1. Build circuit
1
:
a. Use FIGURE: PT100 BrHalf4W() Four-Wire Half-Bridge Schematic
(p. 262)
as a template.