Sensotec CA2 User manual

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2080 ARLINGATE LANE, COLUMBUS OHIO 43228 [phone]
MODEL CA2
INLINE CHARGE
AMPLIFIER

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Inline Charge Amplifier
Model CA2 User's Guide
Sensotec Part Number: 008-0508-00
Rev. 0: August, 1997
Copyright Notice:
Copyright @ 1993 by SENSOTEC, INC.
2080 Arlingate Lane
Columbus, Ohio 43228
U.S.A.
All rights Reserved.
Printed in U.S.A.
TEL [phone]
FAX [phone]
1-800-848-6564

008-0508-00
TABLE OF CONTENTS
Page Number
CHAPTER 1: INTRODUCTION
1.1 Overview..........................................
1.2 Specifications...................................
1.3 Layout..............................................
CHAPTER 2: INSTALLATION / SET UP
2.1 Wiring................................................
2.2 Sensitivity Switch Setup....................
2.3 Panel Mounting Information...............
CHAPTER 3: CALIBRATION
3.1 Calibration.........................................
3.2 Long Time Constant Option..............
CHAPTER 4: WARRANTY / REPAIR POLICY
4.1 Limited Warranty on Products............
4.2 Obtaining Service Under Warranty....
4.3 Obtaining Non-Warranty Service.......
4.4 RepairWarranty................................
APPENDIX A......................................................
1-1
1-1
1-2
2-1
2-2
2-3
3-1
3-3
4-1
4-1
4-2
4-2
A-1

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Chapter 1
INTRODUCTION
1.1 OVERVIEW
Charge mode piezoelectric transducers require charge amplifiers to
converttheiroutputtousefulvoltagelevels. TheSensotecmodel3168
Inline Charge Amplifier is a versatile convenient solution to the use of
chargemodepiezoelectric transducers. The inline is housedina small
metal package which is connected between the transducers and the
instrumentation. The amplifier features multiple sensitivity settings
creating a flexible measuring system.
1.2 SPECIFICATION
Power Requirements + / - 15 volts DC, or 24 - 32
volts DC (with -Output
voltage = 1/2 of supply)
Amplifier Characteristics
Sensitivity Programmable(.05mV/pCto
6.4 mV/pC)
Input Range 780pC to 100,000pC
Output + / - 5V RMS max
Frequency Response Standard- 3HZ to 30kHz
Long TC-~DC to 30kHz
Time Constant Standard- 50 milliseconds
Long TC- 2,000 seconds
Short Circuit Protected + Output to - Output

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1.3 LAYOUT
Figure 1-1. Layout of Inline Amplifier

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Chapter 2
INSTALLATION / SET UP
2.1 WIRING
The Inline Charge amplifier can be powered from a + / - 15 volts DC or
a 24 to 32 volt single voltage supply. The following diagrams show the
wiring to each type of supply.
Cables should be stripped back 3 inches with the wires stripped and
tinned1/2inch. Connectionstotheterminalblockaremadebypressing
theorangeleversandinsertingthewiresintotheholesnexttothelevers.
The terminal block will accept wire up to AWG 20.
Figure 2-1. + / - 15 Volt Power Supply to Inline Wiring
Figure 2-2. 24 - 32 Single Voltage Supply To Inline

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Multipleswitchcombinationscanbeactivatedtoattainadditionalsensi-
tivities. Forexample, if 1mV/pC isdesired then switches 4and6 would
be on. (.8V/pC+.2mV/pC=1mV/pC).
The factory default setting is 1mV/pC. DO NOT use the fine gain
adjustment potentiometer unless you are re-calibrating the charge
amplifierorifyou are scaling the output to aknowninput. Adjustingthe
fine gain potentiometer changes the sensitivities listed in table 2-1.
IfthecustomerrequestsSensotectoset-upthetransducerandCA2for
a single sensitivity, the coarse and fine gain adjustment should not be
altered. In this event the customer loses the flexibility of sensitivity
adjustment. Table 2-1 no longer applies.
Table 2-1. Coarse Gain Setup
2-2
2.2 SENSITIVITY SELECT
The connection to the sensor is thru a low noise miniature coaxial
cable. Cable length should be as short as possible to minimize noise.
Figure 2-2. Sensor to Inline Wiring

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2.3 PANEL MOUNTING INFOMATION
The inline can be easily mounted to a panel by using the template in
Appendix A for marking the holes in the panel. The cover must be
removed to get access to the mounting holes. Use # 6 or # 8 screws for
mounting box to panel.
Actual size not shown. See Appendix A for Template.
Figure 2-3. Panel Mounting Layout

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Chapter 3
CALIBRATION
3.1 CALIBRATION
Step 1. Apply power and allow unit to stabilize for 10 minutes.
Step 2. Calculate sensitivity switch based on desired mV/g or mV/lb
output. Use the following formulas:
Sensitivity = Desired mV/g
mV/pC Accelerometer Sensitivity pC/g
or
= Desired mV/lb
Load Cell Sensitivity pC/lb
EXAMPLES
Example # 1: Sensitivity of the accelerometer = 100pC/g
Desired mV/g = 10
Sensitivity = 10 mV/g
mV/pC 100 pC/g
= .1mV/pC (switch 7)
Example # 2: Sensitivity of load cell = 10pC/lb
Desired mV/lb = 20
Sensitivity = 20 mV/lb
mV/pC 10 pC/lb
= 2 mV/pC (switches 3 and 5)

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Example # 4: Sensitivity of load cell = 10 pC/lb
Full scale lb's = 500
Full scale output at 500 lb's = 5V
a.) 5V = 10mV/lb
500 lb
b.) Sensitivity = 10 mV/lb = 1mV/pC
mV/pC 10 pClb
Example # 3: Sensitivity of accelerometer = 100 pC/g
Full scale g's = 50
Full scale output at 50g's = 5V
a.) 5V = .1V/g = 100 mV/g
50g
b.) Sensitivity = 100mV/g = 1mV/pC
mV/pC 100 pC/g (switches 4 and 6)

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3.2 LONG TIME CONSTANT OPTION
If the long TC option was purchased there will be a front panel toggle
switch labeled LONG or NORMAL. Normal TC indicates the standard
time constant of 50 milliseconds. Long TC indicates a time constant of
2000seconds. ThelongTCoptionisusedtomeasurequasistatic(near
static) events and or to calibrate the sensor under static conditions.
During dynamic measurements reset the long TC toggle switch to
normal.
Quasistatic set-up examples:
3-3
3 ) Switch in normal mode.
4 ) Apply weight to load cell.
5 ) Toggle switch to long TC.
6 ) Quickly remove weight from load cell and note output voltage.
To insure accuracy the test must be performed as quickly as pos-
sible. The decay of the first 10% of the TC is linear. With a TC of
2000 seconds, we can conclude:
20 seconds = 1% accuracy
40 seconds = 2% accuracy
60 seconds = 3% accuracy
Set sensitivity switches based on full-scale = 5V @ 50 lbs
1 ) Calculate mV/lb:
5V = .1V/lb = 100 mV/lb
50 lb
2 ) Calculate switch settings:
Sensitivity = 100 mV/lb = 5 mV/pC
20 pC/lb (switches 2, 3, 6)

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Chapter 4
WARRANTY / REPAIR POLICY
4.1 LIMITED WARRANTY ON PRODUCTS
Any of our products which, under normal operating conditions, proves
defective in material in workmanship within one year from the date of
shipment by SENSOTEC, will be repaired or replaced free of charge
providedthatyouobtainareturnmaterialauthorizationfromSENSOTEC
and send the defective product, transportation charges prepaid with
notice of the defect, and establish that the product has been properly
installed,maintained,andoperatedwithinthelimitsofratedandnormal
usage. Replacement product will be shipped F.O.B. our plant. The
termsofthiswarrantydonotextendtoanyproductorpartthereofwhich,
undernormalusage,hasaninherentlyshorterusefullifethanoneyear.
The replacement warranty detailed here is the buyer’s exclusive rem-
edy, and will satisfy all obligations of SENSOTEC whether based on
contract, negligence, or otherwise. SENSOTEC is not responsible for
anyincidental or consequential loss ordamagewhichmightresultfrom
a failure of any SENSOTEC product. This express warranty is made in
lieuofanyandallotherwarranties,expressorimplied,includingimplied
warranty of merchantability or fitness for particular purpose. Any
unauthorized disassembly or attempt to repair voids this warranty.
4.2 OBTAINING SERVICE UNDER WARRANTY
Advanced authorization is required prior to the return to SENSOTEC.
Beforereturningtheitems,eitherwritetotheCustomerServiceDepart-
ment c/o SENSOTEC, Inc., 2080 Arlingate Lane, Columbus, Ohio
43228,orcall(800) 848-6564with:1)apart number;2)aserialnumber
forthedefectiveproduct;3)atechnicaldescription*ofthedefect;4)ano-
charge purchase order number (so products can be returned to you
correctly);and5)shipandbilladdresses. ShipmenttoSENSOTECshall
beatBuyer’sexpenseandrepairedorreplacementitemswillbeshipped
F.O.B. our plant in Columbus, Ohio. Non-verified problems or defects
may be subject to an evaluation charge. Please return the original
calibration data with the unit.

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4.3 OBTAINING NON-WARRANTY SERVICE
Advance authorization is required prior to the return to SENSOTEC.
Before returning the item, either write to the Customer Service Depart-
ment c/o SENSOTEC, Inc., 2080 Arlingate Lane, Columbus, Ohio
43228, or call [phone] with: 1) a model number; 2) a serial
number for the defective product; 3) a technical description* of the
malfunction;4) a purchase order numberto cover SENSOTEC’s repair
cost; and 5) ship and bill addresses. After the product is evaluated by
SENSOTEC, we will contact you to provide the estimated repair costs
before proceeding. Shipment to SENSOTEC shall be at Buyer’s ex-
pense and repaired items will be shipped to you F.O.B., our plant in
Columbus,Ohio. Pleasereturntheoriginalcalibrationdatawiththeunit.
4.4 REPAIR WARRANTY
AllrepairsofSENSOTECproductsarewarrantedforaperiodof90days
fromdate of shipment. Thiswarranty applies onlyto those itemswhich
werefounddefectiveandrepaired,itdoesnotapplytoproductsinwhich
no defect was found and returned as is or merely recalibrated. Out of
warranty products may not be capable of being returned to the exact
original specifications or dimensions.
* Technical description of the defect: In order to properly repair a
product,itisnecessaryforSENSOTECtoreceiveinformationspecifying
the reason the product is being returned. Specific test data, written
observationsonthefailureandthespecificcorrectiveactionyourequire,
is needed.
4-2

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Figure A-1. Panel Mounting Template
APPENDIX A