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Table of Contents 

ii 

B.

 

Example Program ................................................... B-1

 

Figures 

1-1.  AM25T Solid-State Thermocouple Multiplexer ................................. 1

 

5-1.  AM25T Solid-State Thermocouple Multiplexer with cover................ 4

 

7-1.  External Battery Connections .............................................................. 6

 

7-2.  Differential Measurement of Type T Thermocouple ........................... 8

 

7-3.  Differential Voltage Measurement ...................................................... 8

 

8-1.  Short Cut ............................................................................................. 9

 

Tables 

7-1.  AM25T to Datalogger Wiring ............................................................. 7

 

CRBasic Example 

B-1.  CR6 Program Using One Instruction to Measure Both the  

Reference Temperature and Thermocouples................................ B-1

 

 

 

Summary of Contents for AM25T

Page 1: ...INSTRUCTION MANUAL AM25T Solid State Thermocouple Multiplexer Revision 4 17 C o p y r i g h t 1 9 9 5 2 0 1 7 C a m p b e l l S c i e n t i f i c I n c ...

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Page 3: ...ducts to CSI CSI will return such Products by surface carrier prepaid within the continental United States of America To all other locations CSI will return such Products best way CIP port of entry per Incoterms 2010 This warranty shall not apply to any Products which have been subjected to modification misuse neglect improper service accidents of nature or shipping damage This warranty is in lieu...

Page 4: ... address is CAMPBELL SCIENTIFIC INC RMA _____ 815 West 1800 North Logan Utah 84321 1784 For all returns the customer must fill out a Statement of Product Cleanliness and Decontamination form and comply with the requirements specified in it The form is available from our website at www campbellsci com repair A completed form must be either emailed to repair campbellsci com or faxed to 435 227 9106 ...

Page 5: ...e beginning work Wear a hardhat and eye protection and take other appropriate safety precautions while working on or around tripods and towers Do not climb tripods or towers at any time and prohibit climbing by other persons Take reasonable precautions to secure tripod and tower sites from trespassers Use only manufacturer recommended parts materials and tools Utility and Electrical You can be kil...

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Page 7: ...r Ground G Ground Terminals 3 4 5 Analog Ground 3 4 6 Reset RES 3 4 7 Clock CLK 3 5 Overview 4 6 Specifications 4 7 Installation 5 7 1 Installing the AM25T 5 7 2 Datalogger to AM25T Wiring 6 7 3 Sensor to AM25T Wiring 7 7 3 1 Thermocouple Measurement 7 7 3 2 Differential Analog Measurements 8 7 3 3 Mixed Sensor Types 8 8 Operation 8 8 1 General Measurement Considerations 8 8 2 Datalogger Programmi...

Page 8: ...uple Multiplexer with cover 4 7 1 External Battery Connections 6 7 2 Differential Measurement of Type T Thermocouple 8 7 3 Differential Voltage Measurement 8 8 1 Short Cut 9 Tables 7 1 AM25T to Datalogger Wiring 7 CRBasic Example B 1 CR6 Program Using One Instruction to Measure Both the Reference Temperature and Thermocouples B 1 ...

Page 9: ...suitable for resistive bridge measurements high impedance of the solid state relays or multiplexing power 25 mA maximum switching current A maximum of 25 thermocouples differential voltage measurement can be multiplexed by an AM25T Single ended voltage measurements are not recommended The AM25T must be used in a noncondensing environment An enclosure is required for field use In applications where...

Page 10: ...ing material for product that may be concealed Check model number part numbers and product descriptions against the shipping documents Model or part numbers are found on each product On cables the number is often found at the end of the cable that connects to the measurement device Ensure that the expected lengths of cables were received Contact Campbell Scientific immediately if there are any dis...

Page 11: ... the terminal located between the VX and HI terminals Analog ground is not common with the other ground terminals labeled The analog ground terminal must be connected to the datalogger ground as shown in TABLE 7 1 4 6 Reset RES A control port is used to operate the RES channel The AM25T is reset and activated by applying and holding 5 Vdc to the RES channel Once the AM25T is activated the AM25T re...

Page 12: ...ad wires up to 1 5 mm 0 059 inches in diameter A strain relief flange is located between the input terminals FIGURE 5 1 AM25T Solid State Thermocouple Multiplexer with cover 6 Specifications Power Unregulated 9 6 to 16 Vdc 12 Vdc nominal Current Drain Quiescent 0 5 mA Active 1 0 mA typical Enable Inactive 0 9 V Active 3 5 to 5 0 V 7 V max Clock The relays are advanced on the falling edge of the cl...

Page 13: ...um Switching Current 25 mA switching currents greater than 25 mA will damage the relays and render them unusable Compliance View the EU Declaration of Conformity at www campbellsci com am25t Assumes sequential activation of multiplexers and that each datalogger channel is uniquely dedicated If your application requires additional multiplexing capability please consult Campbell Scientific for appli...

Page 14: ...parate battery might be used when the AM25T is installed some distance from the datalogger Ground must be connected between the datalogger and the AM25T FIGURE 7 1 FIGURE 7 1 External Battery Connections When leads in excess of 152 m 500 feet are used to connect the datalogger to the AM25T it may be necessary to compensate for the drop in PRT excitation voltage All AM25T inputs are spark gap prote...

Page 15: ...datalogger input to measure the reference Thermal gradients between the AM25T sensor input terminals and the PRT cause errors in thermocouple readings For example a one degree gradient between input terminals and the PRT will result in a one degree measurement error The thermal bar in the AM25T which includes the strain relief and the AM25T cover are designed to reduce gradients The PRT is attache...

Page 16: ...r Types Different sensors may be mixed on the AM25T Additional loops and measurement instructions will be required 8 Operation 8 1 General Measurement Considerations Cables have additional capacitance that increases the time required for a signal to settle its true value To reduce settling time Campbell Scientific Control Power Datalogger Copper Copper GND 1H 1L VX AM25T H L VX Analog Ground1 1H 1...

Page 17: ...figurations for various supported sensors providing a quick way to generate a program and wiring diagram FIGURE 8 1 Short Cut can be downloaded free of charge www campbellsci com FIGURE 8 1 Short Cut Short Cut is the best source for up to date datalogger programming code Programming code is needed when Creating a program for a new datalogger installation Adding sensors to an existing datalogger pr...

Page 18: ... reference temperature for thermocouple measurements The AM25T instruction and parameters are as follows AM25T Dest Reps Range AM25TChan DiffChan TCType TRef ClkPort ResPort ExChan RevDiff SettlingTime Integ fN1 Mult Offset For information on this instruction refer to the CRBasic Help 9 Maintenance Maintain a level of calibration appropriate to the application Campbell Scientific recommends factor...

Page 19: ...e Open Assuming the default paths were used when Short Cut was installed navigate to C CampbellSci SCWin folder The file of interest has the CR6 CR8 CR1 CR3 CR5 or CR9 extension Select the file and click Open 3 Immediately save the file in a folder different from C Campbellsci SCWin or save the file with a different file name Once the file is edited with CRBasic Editor Short Cut can no longer be u...

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Page 21: ...n High HI U5 Common Low LO U6 1 Analog Ground is the terminal located between the VX and HI terminals on the AM25T CRBasic Example B 1 CR6 Program Using One Instruction to Measure Both the Reference Temperature and Thermocouples CR6 Series Declare Variables and Units Public BattV Public PTemp_C Public RTempC Public Temp_C 25 Units BattV Volts Units PTemp_C Deg C Units RTempC Deg C Units Temp_C Deg...

Page 22: ...ry BattV Default CR6 Datalogger Wiring Panel Temperature measurement PTemp_C PanelTemp PTemp_C 60 Type T copper constantan Thermocouple measurements Temp_C on the AM25T Multiplexer AM25T Temp_C 25 mv200C 1 U5 TypeT RTempC U1 U2 U3 True 0 60 1 0 Call Data Tables and Store Data CallTable Dat15sec CallTable Dat5Min NextScan EndProg ...

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Page 24: ...Rua Apinagés nbr 2018 Perdizes CEP 01258 00 São Paulo SP BRASIL www campbellsci com br vendas campbellsci com br Campbell Scientific Canada Corp 14532 131 Avenue NW Edmonton AB T5L 4X4 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientific Centro Caribe S A 300 N Cementerio Edificio Breller Santo Domingo Heredia 40305 COSTA RICA www campbellsci cc info campbellsci cc Campbell Sci...

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