Section 5. Overview
75
5.2.2.2 Current Measurements — Overview
Related Topics:
•
Current Measurements — Overview
(p. 75)
•
Current Measurements — Details
(p. 415)
A measurement of current is accomplished through the use of external resistors to
convert current to voltage, then measure the voltage as explained in the section
Differential Measurements — Overview
The voltage is measured with the
CR6 voltage measurement circuitry.
U
terminals can be configured to supply
precise current excitation for use with resistive bridges.
5.2.2.3 Resistance Measurements — Overview
Related Topics:
•
Resistance Measurements — Specifications
(p. 106)
•
Resistance Measurements — Overview
(p. 75)
•
Resistance Measurements — Details
(p. 406)
•
Measurement: RTD, PRT, PT100, PT1000
(p. 326)
Many analog sensors use some kind of variable resistor as the fundamental
sensing element. As examples, wind vanes use potentiometers, pressure
transducers use strain gages, and temperature sensors use thermistors. These
elements are placed in a Wheatstone bridge or related circuit. With the exception
of PRTs, another type of variable resistor. See
Measurement: RTD, PRT, PT100,
PT1000
(p. 326).
This manual does not give instruction on how to build variable
resistors into a resistor bridge. Sensor manufacturers consider many criteria
when deciding what type of resistive bridge to use for their sensors. The CR6
can measure most bridge circuit configurations.
5.2.2.3.1 Voltage Excitation
Bridge resistance is determined by measuring the difference between a known
voltage applied to the excitation (input) arm of a resistor bridge and the voltage
measured on the output arm. The CR6 supplies a precise-voltage excitation via
U
terminals configured for voltage excitation output. Return voltage is measured
on
U
terminals configured for single-ended or differential input. Examples of
bridge-sensor wiring using voltage excitation are illustrated in figures
Half-Bridge
Wiring — Wind Vane Potentiometer
(p. 76)
and
Full-Bridge Wiring — Pressure
Transducer
(p. 77).
Summary of Contents for CR6 Series
Page 2: ......
Page 4: ......
Page 6: ......
Page 32: ......
Page 36: ......
Page 38: ......
Page 76: ...Section 5 Overview 76 FIGURE 20 Half Bridge Wiring Example Wind Vane Potentiometer ...
Page 80: ...Section 5 Overview 80 FIGURE 23 Pulse Input Wiring Example Anemometer ...
Page 136: ......
Page 454: ...Section 8 Operation 454 FIGURE 104 Narrow Sweep High Noise ...
Page 459: ...Section 8 Operation 459 FIGURE 106 Vibrating Wire Sensor Calibration Report ...
Page 535: ...Section 8 Operation 535 8 11 2 Data Display FIGURE 121 CR1000KD Displaying Data ...
Page 537: ...Section 8 Operation 537 FIGURE 123 CR1000KD Real Time Custom ...
Page 538: ...Section 8 Operation 538 8 11 2 3 Final Storage Data FIGURE 124 CR1000KD Final Storage Data ...
Page 539: ...Section 8 Operation 539 8 11 3 Run Stop Program FIGURE 125 CR1000KD Run Stop Program ...
Page 541: ...Section 8 Operation 541 FIGURE 127 CR1000KD File Edit ...
Page 546: ......
Page 552: ......
Page 610: ...Section 11 Glossary 610 FIGURE 137 Relationships of Accuracy Precision and Resolution ...
Page 612: ......
Page 648: ......
Page 650: ......
Page 688: ......
Page 689: ......