Related Manuals for Campbell 253
Summary of Contents for Campbell 253
- Page 1 Model 253 and 253-L (Watermark 200) Soil Moisture Sensor Revision: 6/96 C o p y r i g h t ( c ) 1 9 9 3 - 1 9 9 6 C a m p b e l l S c i e n t i f i c , I n c .
- Page 2 WARRANTY AND ASSISTANCE This equipment is warranted by CAMPBELL SCIENTIFIC (CANADA) CORP. (“CSC”) to be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless specified otherwise. ***** Batteries are not warranted.
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Page 3: Table Of Contents
253 Table of Contents PDF viewers note: These page numbers refer to the printed version of this document. Use the Adobe Acrobat® bookmarks tab for links to specific sections. 1. General ................1 2. Installation and Removal..........1 3. Wiring ................2 4. Measurement...............2 4.1 Calculate Sensor Resistance - Instruction 59 ..........2... - Page 4 This is a blank page.
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Page 5: General
Typically, the sensor Scientific CR10, 21X, or CR7 datalogger. CSI must be located in the root system of the crop. Models 253 and 253-L are for connection to the AM32 or AM416 Analog Multiplexers. Models 1. Soak the sensors overnight in irrigation 257 and 257-L connect directly to a datalogger. -
Page 6: Wiring
3. WIRING Soil temperatures vary widely where placement is shallow and solar radiation impinges on the The model 253 sensor is supplied with two green soil surface. A soil temperature measurement leads from Watermark. The leads from the may be needed in such situations, particularly in Watermark electrode are connected directly to research applications. -
Page 7: Programming (Measuring Block Resistance)
253 AND 253-L SOIL MOISTURE SENSOR Beginning of Loop 4.2.2 Non-Linear Relationship Delay For more precise work, calibration and temperature Loop Count compensation in the range of 0.1 to 1.00 bar has Excitation with delay (clock) been refined by Thompson and Armstrong (1987),... -
Page 8: Am32 And Cr10
253 AND 253-L SOIL MOISTURE SENSOR 5.2 AM32 AND CR10 See Figure 5.2 for wiring diagram. This program can also be used with 21Xs with OSX PROMs although the clock pulse delay is 0.1 seconds (Figure 5.3). Set Port 5 high... -
Page 9: Am416 And Cr10
253 AND 253-L SOIL MOISTURE SENSOR FIGURE 5.4 Figure 5.5 5.4 AM416 AND CR10 See Figure 5.5 for wiring diagram. This program can also be used with 21X with OSX PROMs although the clock pulse delay is 0.1 seconds (Figure 5.6). -
Page 10: Non-Linear Resistance And Temperature Relationship (0.1 To 1 Bar)
253 AND 253-L SOIL MOISTURE SENSOR Z=X+F X Loc CorrFactr 34.21 Z Loc [:CorrFactr] Z Loc [:Constant ] Z=X*F SWP = 34.21-Ts X Loc CorrFactr Z=X-Y Z Loc [:CorrFactr] X Loc Constant Y Loc Tsoil C Apply Temperature Correction and Z Loc [:Constant ] Sensor Calibration to Ohm Measurements. -
Page 11: Programming (Comprehensive)
253 AND 253-L SOIL MOISTURE SENSOR Step 4. Make the resistance measurements. 7. PROGRAMMING (COMPREHENSIVE) It may be appropriate to make Follow these steps to create a complete measurements only once or twice a program: day. This example makes measurements twice a day at 6:00 AM Step 1. -
Page 12: Interpreting Results
253 AND 253-L SOIL MOISTURE SENSOR 3. When the soil dries out to the point where 8. INTERPRETING RESULTS you are seeing readings higher than 80 As a general guide, Watermark 200 centibars, the contact between soil and measurements indicate soil moisture as follows: sensor can be lost because the soil may start to shrink away from the sensor. - Page 13 This is a blank page.
- Page 14 Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za sales@csafrica.co.za Campbell Scientific Australia Pty. Ltd. (CSA)