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USER’S MANUAL 

 

MODEL 781 SIGNAL CONDITIONING UNIT 

 

 

Serial No.________________ 

 
 

 

 
 
 
 

 
 

 

850 Perimeter Road 

Manchester, NH  03103  USA 

Tel (603) 669-6400 

Fax (603) 622-2690 

[email protected] 

www.jewellinstruments.com

 

 
 
 
 

 
 

 
 
 
 
 
 

 

Copyright ©2013 by Jewell Instruments LLC.  All rights reserved. 

Document No. B-88-1006, Rev. B 

 

Summary of Contents for 781

Page 1: ...T Serial No ________________ 850 Perimeter Road Manchester NH 03103 USA Tel 603 669 6400 Fax 603 622 2690 sales jewellinstruments com www jewellinstruments com Copyright 2013 by Jewell Instruments LLC All rights reserved Document No B 88 1006 Rev B ...

Page 2: ... 1 Introduction 2 1 2 General Specifications 2 2 0 Operation 6 2 1 Using the Controls Meaning of the Indicators 6 3 0 Maintenance and Troubleshooting 7 3 1 Routine Maintenance 7 3 2 Determining the Cause of Malfunctions 8 A Warranty and Assistance 9 B Custom Specification for your Equipment 10 C Revision Table 12 ...

Page 3: ... control switches on the front panel of the SCU and the input and output terminals on the rear panel Figures 1 and 2 Basic maintenance and troubleshooting guidelines are given in the last section of the manual 1 2 General Specifications INPUT CHANNELS Two Jewell Instrument electrolytic tilt sensors one LM 35 temperature sensor TILT OUTPUT Two channels of single ended and differential analog output...

Page 4: ...l barrier strips TEMPERATURE RANGE 20 C to 70 C 4 F to 158 F Operational 30 C to 100 C 22 F to 212 F Storage HUMIDITY RANGE 0 to 100 noncondensing nonsubmersible SIZE 3 5 x 5 x 8 4 8 8 cm x 12 7 cm x 21 3 cm WEIGHT 2 lbs 0 9 kg MATERIALS Case painted aluminum ...

Page 5: ...B 88 1006 REV B 4 ...

Page 6: ...B 88 1006 REV B 5 ...

Page 7: ...three terminal positions E and are for the three lead wires from the first tilt sensor E is the center or neutral wire and are the positive and negative pick ups respectively For color coding of the sensor lead wires supplied with your SCU see Appendix B SENSOR 2 The three terminal positions E and are for the three lead wires from the second tilt sensor TEMP SENSOR The three terminal positions T1 ...

Page 8: ... DC to this terminal PWR GND Connect the power ground power common to this terminal 12 V Connect 11 to 15 volts DC to this terminal 3 0 MAINTENANCE AND TROUBLESHOOTING 3 1 Routine Maintenance The SCU is rugged and should require no maintenance other than occasional cleaning of the box with a soft cloth Keep the SCU and tilt sensor from extremes of heat and cold Extreme temperatures unnecessarily s...

Page 9: ...in each side panel then gently lift away the SCU top panel Small plastic connectors are used to attach the tilt and temperature sensor leads to the printed circuit board Check to be sure that these connectors have not become loose or detached If you remove any of these small plastic connectors be sure to replace the Sensor 1 Sensor 2 and temperature connectors exactly as you found them Figure 2 sh...

Page 10: ...oid if the equipment is subjected to lighting strikes or other large potential gradients or if it is otherwise abused After expiration of the warranty Jewell will repair the equipment at its factory for parts and labor charges Products returned after warranty expiration should be accompanied by a purchase order to cover repair costs Jewell Instruments is not liable for consequential damages The re...

Page 11: ...ting is listed below After an instantaneous change in tilt the output signal settles to 90 of this value after three time constants and to 98 of this value after four time constants The corner or cutoff frequency ƒc is defined as the frequency at which signal attenuation is 3 dB Filter roll off above the corner frequency is constant at 6 dB per octave 20 dB per decade Corner frequency can be calcu...

Page 12: ... Scale Factors are expressed as angular change per volt differential Scale Factors are one half single ended Scale Factors SCU serial number ____________ Calibration range units ____________ Scale Factor units ____________ SENSOR 1 CHANNEL Transducer Serial No Calib Temp F Calib Range Scale Factors Single ended Differential High Gain Low Gain High Gain Max Nonlinearity Low Gain Max Nonlinearity SE...

Page 13: ...B 88 1006 REV B 12 APPENDIX C Revision Table REV PAGE NOS ECN NO DESCRIPTION OF CHANGE DATE B ALL 25087 Jewell was Applied Geomechanics Added Appendix C for revision record 2 13 13 ...

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