Campbell AM32, Instruction Manual

AM32 Table of Contents

ii

8.  General Measurement Considerations....................21

9.  Installation.................................................................21

9.1  Environmental Constraints ..................................................................... 22

10.  Differences between the AM32 and the AM416 ....22

List of Figures

1-1.  Plan View of the AM32 Relay Multiplexer with Cover Plate
Removed ......................................................................................................... 1
3-1.  Hook-up Diagrams for Datalogger to AM32 Connections ..................... 3
3-2.  Power and Ground Connections for External Power Supply .................. 4
3-3.  Actuation Time of Relays Versus Temperature (

°

C) and Battery

Voltage............................................................................................................ 4
4-1.  Single Loop Instruction Sequence .......................................................... 5
5-1.  Single-Ended Measurement .................................................................... 7
5-2.  Differential Measurement ....................................................................... 9
5-3.  Half Bridge Measurement with Resistor at the Datalogger..................... 9
6-1.  Differential Thermocouple Measurement with Reference Junction
at the Datalogger ........................................................................................... 10
6-2.  Differential Thermocouple Measurement with Reference Junction
at the AM32 .................................................................................................. 10
7-1.  Wiring Diagram for CR10(X), AM32 and 223 Soil Moisture Block
Example ........................................................................................................ 11
7-2.  Wiring Diagram for 21X and Thermocouples with Reference at the
Datalogger..................................................................................................... 14
7-3.  Wiring Diagram for Example of CR10(X) Measuring Soil Moisture
Blocks and Thermocouples with Reference Temperature at the AM32 ........ 16
7-4.  Wiring Diagram for Example Using 21X Datalogger to Measure
107 Temperature Probes ............................................................................... 20

List of Tables

3-1.  CR10(X)/AM32 Average Current Drain Making Differential
Measurements on 32 Thermocouples.............................................................. 5
5-1.  Example Programs - Generalized Program Loops for the 21X,
CR10(X), and CR7.......................................................................................... 8