Astronics Trig-Tek 203M User Manual

Trig-Tek™

203M

Charge Amplifier

User Manual

Publication No. 98 0 978 Rev. A

Astronics Test Systems Inc.

4 Goodyear, Irvine, CA 92618

Tel: [phone]; Fax: [phone]

[email protected] [email protected]

[email protected] http://www.astronicstestsystems.com

Copyright 2011 by Astronics Test Systems Inc. Printed in the United States of America. All rights reserved.
This book or parts thereof may not be reproduced in any form without written permission of the publisher.

THANK YOU FOR PURCHASING THIS

ASTRONICS TEST SYSTEMS PRODUCT

For this product, or any other Astr onics Test Systems produc t that incorporat es software drivers,
you may access our web site to verify and/or download the latest driver versions. The web
address for driver downloads is:

http://www.astronicstestsystems.com/support/downloads

If you have any questions about software driver downloads or our privacy policy, please contact
us at:

[email protected]

WARRANTY STATEMENT

All Astronics Test Systems products are desig ned to exacting standards and manufact ur ed in full
compliance to our AS9100 Quality Management System processes.

This warranty does not apply to defects resulting from any modification(s) of any product or part
without Astronics Test Systems express written consent, or misuse of any product or part. The
warranty also does not apply to fuses, software, non-rechargeable batteries, damage from
battery leakage, or problems arising f rom normal wear, such as m echanical relay life, or failure to
follow instructions.

This warranty is in lieu of all other warranties, expressed or implied, including any implied
warranty of merchantability or fitness for a particular use. The remedies provided herein are
buyer’s sole and exclusive remedies.

For the specific terms of your standard warranty, contact Customer Support . Please have the
following information available to facilitate service.

1. Product serial number

2. Product model number

3. Your company and contact information

You may contact Customer Support by:

E-Mail: [email protected]
Telephone: [phone] (USA)
Fax: [phone] (USA)

RETURN OF PRODUCT

Authorization is required from Astronics Test Systems before you send us your product or sub-ass embly for
service or calibration. Call or contac t Custom er Support at 1-800-722-3262 or 1-949-859-8999 or via fax at
1-949-859-7139. We can also be reached at: [email protected].

If the original packing material is unavailable, ship the product or sub-assembly in an ESD shielding bag and
use appropriate packing materials to surround and protect the product.

PROPRIETARY NOTICE

This document and the technic al data herein disc los ed, are pr oprietar y to Astronics Test Systems, and shall
not, without express written permission of Astronics Test Systems, be used in whole or in part to solicit
quotations from a competitive source or used for manufacture by anyone other than Astronics Test
Systems. The information herein has been developed at private expense, and may only be used for
operation and maintenance referenc e purposes or for purposes of engineering evaluation and incorporation
into technical specifications and other documents which specify procurement of products from Astronics
Test Syste ms.

TRADEMARKS AND SERVICE MARKS

All trademarks and service marks used in this document are the property of their respective owners.

• Racal Instruments, Talon Instruments, Trig-Tek, ActivATE, Adapt-A-Switch, N-GEN, and PAWS are
trademarks of Astronics Test Systems in the United States.

DISCLAIMER

Buyer acknowledges and agrees that it is responsible for the operation of the goods purchased and should
ensure that they are used properly and in accordance with this document and any other instructions
provided by Seller. Astronics Test Systems products are not specifically designed, manufactured or
intended to be used as parts, assemblies or components in planning, construction, maintenance or
operation of a nuclear facility, or in life support or safety critical applications in which the failure of the
Astronics Test Systems product could create a situation where personal injury or death could occur. Should
Buyer purchase Astronics Test Systems product for such unintended application, Buyer shall indemnify and
hold Astronics Test Systems, its officers, employees, subsidiaries, affiliates and distributors harmless
against all claims arising out of a claim for personal injury or death associated with such unintended use.

ains voltage hazardous to

of the power

ective feature of the third

FOR YOUR SAFETY

Before undertaking any troubleshooting, maintenance or exploratory procedure, read carefully the
WARNINGS and CAUTION notices.

This equipment cont
human life and safety, and is capable of inflicting

If this instrument is to be powered f rom the AC line (mains) through an autotransform er,
ensure the common connector is connected to the neutral (earth pole)
supply.

personal injury.

Before operating the unit, ens ure the conduc tor (green wire) is connected to the ground
(earth) conductor of the power outlet. Do not use a two-conductor extension cord or a
three-prong/two-prong adapter. This will defeat the prot
conductor in the power cord.

Maintenance and calibration procedures sometimes call for operation of the unit with
power applied and protective covers removed. Read the proc edures and heed warnings
to avoid “live” circuit points.

Before operating this instrument:

1. Ensure the proper fuse is in place for the power source to operate.

2. Ensure all other devices connected to or in proximity to this instrument are properly grounded or
connected to the protective third-wire earth ground.

If the instrument:

- fails to operate satisfactorily

- shows visible damage

- has been stored under unfavorable conditions

- has sustained stress

Do not operate until performance is checked by qualified personnel.

Publication No. 980978 Rev. A 203M User Manual

Table of Contents

Chapter 1 ......................................................................................................................... 1-1

Introduction ..................................................................................................................... 1-1

System Description ........................................................................................................................ 1-2

General....................................................................................................................................... 1-2

System Specifications .................................................................................................................... 1-3

Input ........................................................................................................................................... 1-3

Acceleration Outputs (NOR and AUX) ....................................................................................... 1-4

Velocity Output ........................................................................................................................... 1-4

Displacement Output .................................................................................................................. 1-5

DC Output .................................................................................................................................. 1-5

Controls ...................................................................................................................................... 1-6

Indicators .................................................................................................................................... 1-7

Power ......................................................................................................................................... 1-7

Size ............................................................................................................................................ 1-7

Chapter 2 ......................................................................................................................... 2-1

Operation ......................................................................................................................... 2-1

Input Switch ................................................................................................................................ 2-1

Digital Panel Meter ..................................................................................................................... 2-1

Units Switch ................................................................................................................................ 2-1

METER RANGE Switch ............................................................................................................. 2-2

Sensitivity (RANGE) 1-11 or 10-110 Switch ............................................................................... 2-2

SENSITIVITY Control ................................................................................................................. 2-2

SE-DIFF Switch .......................................................................................................................... 2-2

OPER-CAL Switch ..................................................................................................................... 2-2

MV/g Output Switch .................................................................................................................... 2-3

LP FILTER Switch ...................................................................................................................... 2-3

HOLD Circuit .............................................................................................................................. 2-3

ALARM Circuit ............................................................................................................................ 2-3

RMS-PEAK Switch ..................................................................................................................... 2-4

Chapter 3 ......................................................................................................................... 3-1

Performance Test ............................................................................................................ 3-1

Test Equipment .............................................................................................................................. 3-1

Performance Test Procedure ......................................................................................................... 3-1

Control Settings .............................................................................................................................. 3-2

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203M User Manual Publication No. 980978 Rev. A

Chapter 4 ........................................................................................................................ 4-1

Calibration Procedure .................................................................................................... 4-1

Test Equipment ...........................................................................................................................4-1

Switch Settings ...........................................................................................................................4-1

Charge Converter and Displacement Adjust ..............................................................................4-2

DVM Adjustments .......................................................................................................................4-2

Calibrator Adjustments ...............................................................................................................4-3

.

ii Astronics Test Systems

Publication No. 980978 Rev. A 203M User Manual

List of Figures

Figure 1-1, 203M Charge Amplifier .................................................................................................... 1-2

Figure 4-1, 203M Adjustment Locations ............................................................................................ 4-3

Figure 4-2, DVM Adjustment Resistor R1 .......................................................................................... 4-4

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DOCUMENT CHANGE HISTORY

Revision Date Description of Change

A 06/14/2011 Document Control release

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vi Astronics Test Systems

Publication No. 980978 Rev. A 203M User Manual

Chapter 1

Introduction

The 203M Charge Amplifier (Figure 1-1) is a versatile charge amplifier covering
the frequency rang e from 5 Hz to 30,000 Hz. It will accommodate sensors with
sensitivities varying from 1 to 110 pC/g or mV/ g and provides an output of either
10 mV/g or 100 mV/g with selectable Peak or RMS indication.

A double integration process provides velocity and displacement outputs. A CAL­OPER switch connects the charge amplifier input to either the calibrate signal or to
the normal input.

Three standard low pass filters with cutoff frequencies of 3, 10, or 30 kHz, other
cutoffs can be supplied at the t im e of order.

The unit will operate with high temperature accelerometers where pyroelectric
effects may be encountered and will function with 1 MegOhm or greater shunt
input resistance. The unit has an alarm circuit to alert if preset levels are
exceeded and a relay contact closure is provided.

The Charge Amplifiers are pack aged in a plug-in module. Up to six modules will
plug into a standard 19-inch cabinet space, seven inches high, or in a single
module cabinet.

Features include:

• pC/g or mV/g

• Accel, Vel, Displ

• 1 to 110 pC or mVg

• DVM Indictor

• Alarm

• Level Hold

• Built-in Calibrator

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203M User Manual Publication No. 980978 Rev. A

System Description

General

The 203M is a versatile charg e amplifier covering the freq uency range from 5 Hz
to 30,000 Hz. It will accept inputs with sensitivities varying from 1 to 110 mV or
pC/g and provides an output of either 10 mV/ g or 100 mV/g with selectable peak
or RMS indication. It also integrates the input signal to provide velocity and
displacement outputs with sensitivities of 10 mV/unit.

Introduction 1-2 Astronics Test Systems

Figure 1-1, 203M Charge Amplifier

Publication No. 980978 Rev. A 203M User Manual

The charge sensitivity control is continuously variable from 1 to 11 with an
additional X10 Switch to allow operating with pickups having sensitivities from 1 to
110 mV or pC/g.

A toggle switch permits selection of eit her 10 mV/g or 100 mV/g output sensitivity.
A CAL-OPER switch connects the charge amplifier input to either internal
calibrator signal or to the norm al input.

A front panel filter switch selects thr ee low pass filter cutoff frequencies of 3, 10,
or 30 kHz marked LOW, MEDIUM, or HIGH.

The unit will operate with high temperature accelerometers where pyroelectric
effects may be encountered. It will function with 1 MegOhm or great shunt input
resistance.

The unit has an alarm circuit to alert if pr eset levels are exceeded. The Charge
Amplifiers are packaged in a plug -in module. Up to six modules will plug into a
standard 19-inch rack space, seven inches high.

System Specifications

Input

Connector BNC.
Charge Sensitivity 1 to 110 mV or pC/g (provided with two

selectable ranges), 1-11 and 10-110 mV or
pC/g with continuous adjustment for each.

Frequency Response

Overload Recovery

Amplitude
(Stability vs. Input c apacit y)

Amplitude
(Stability Temperature)

Shunt Resistance

Filtering

±3% from 5 Hz to 30,000 Hz referred to 100
Hz.

10.000 pC or less, 1 ms half sine input
pulse will cause no effect at the output,
except clipping.

Less than 0.1% change per 1000 pF.

Less than 3% change from 30˚ to 130˚F.
Will operate with any input impedance

above 100k Ohms.
12dB per octave roll off with 3dB cutoffs

selectable for 3 kHz, 10 kHz, and 30kHz.
(Other cutoff frequency supplied on
request)

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203M User Manual Publication No. 980978 Rev. A

Acceleration Outputs (NOR and AUX)

Voltage (Max) 10 Volts RMS.
Sensitivity 10 mV/g or 100 mV/g.

Impedance

Amplitude Linearity

Amplitude Accuracy

Noise

Harmonic Distortion Less than 1%.
DC Offsst Less than 5 millivolts.

Velocity Output

Voltage Max 10 Volt RMS.
Sensitivity 10 mV/in/sec.
Impedance Less than 50 Ohms (10 mA max).

Less than 50 Ohms. (NOR 10 mA max;
AUX 10 mA max.

±1% of best straight line approximation of
output vs. input amplitude.

±2% of reading ±1% of FS in series with
selected Low Pass Filter.

0.05 pC maximum with 1.0 pC/g sensitivity.
Noise increases 0.007g/1000 pF of
additional capacity at the input.

±3% 5 Hz to 30000 Hz of a –6dB/oct slope,

Frequency Response

Dynamic Range 46 dB below full scale.
DC Offset Less than 5 millivolts.

in series with selected input Low Pass
Filter.

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Displacement Out put

Level 0-10 Volts RMS.
Impedance Less than 50 Ohms (20 mA max)
Sensitivity 10 mV/mil DA.
Amplitude Accuracy ±5% of reading ±0.5% FS.

±3% 10 Hz to 10000 Hz of a –12dB slope.

Frequency Response

Dynamic Range 36dB below full scale.

±5% for 5 Hz to 3000 Hz of a –12dB slope
in series with the selected Low Pass Filter.

DC Output

DC Offset

Level 10 Volts DC full scale (meter range).
Impedance Less than 50 Ohms (10 mA max)
Sensitivity 10 Volts for selected full scale.
Linearity 1% full scale.
Amplitude Accuracy 2% of reading ±1% FS.
Dynamic Range (Accel) 60 dB below full scale.

Less than 5 millivolts (noise signal must be
averaged).

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203M User Manual Publication No. 980978 Rev. A

The READ position connects the level

Controls

Filter Switch Selects LOW, MED, and HIGH nominal

–3 dB frequency cutoffs for the Low Pass
Filter.

Cutoff Frequency KHz

LOW MED HIGH
3 10 30

Connects the amplifier input to either t he

CAL-OPER Switch

MV/g Output Switch Selects 10 or 100 mV/g output.

PC/g-mV/g Switch

internal calibrator signal or to the Accel
Input jack.

mV/g accommodates accelerometers with
built-in electronics; while pC/g
accommodates standard accelerometer s .

Sensitivity Switch Selects 1-11, or 10-110 mV/g or pC/g.
Sensitivity Dial

UNITS Switch

FULL SCALE Switch

RMS-PEAK Switch

ALARM SET Switch

SE-DIFF Switch

READ-HOLD Switch

Adjusts the charge sensitivity from 1-11 for
each range.

Selects either g’s IPS or MILS as the meter
units.

Selects 10, 100, or 1000 units as full s c a le
for the meter.

Scales the front panel DVM for either PEAK
or RMS units at the input.

Provides the means of monitoring t he alarm
set point; also RESETS the alarm.

Selects either single-ended or differential
configuration at the input.

stored in the Peak-Hold circuit to the meter,
and the ERASE position resets the Peak­Hold circuit to zero.

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Indicators

CAL Light Illuminates when the CAL mode is selected.
ALARM Light Illuminates when the alarm set point is

exceeded.

Power

Size

115 or 230, 10% Volts, 50-400 Hz, 3 watts
nominal.

7 inches high x 2.7 inches wide x 13 inches
deep; up to six units mounted side by side
in a standard 19-inch wide rack.

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Introduction 1-8 Astronics Test Systems

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Chapter 2

Operation

The 203M Charge Amplifier is in a modular package with a self -contained power
supply. Insert the amplifier into one of the six rack spaces of a six-module rack
or the single-module cabinet. Connect the AC line into either 115 Volts or 220
Volts RMS, 60 Hz power. A switch (S1) m ounted on the circuit board of each
module selects either 110 or 220 Volts operat ion. Operation with this switch set
for 110 Volts when using 220 Volt power will dam age the unit. T he power to the
six modules is controlled by the POWER switch on the left-hand side of t he rack ;
place this switch to POWER.

CAUTION

The 115-230 VAC switch (S1) must be at the proper setting.

Input Switch

The Charge amplifier is designed t o accept inputs from either standard charge
type pickups or from the t ype with the electronics built it . Place t he I NPUT switch
to pC/g for standard c har ge type pickups and to mV/g f or the other. When this
switch is in the mV/g position, a current output is supplied t o oper at e the pickup
electronics. This will be set for 3-5 milliamps when shipped. Connect t he pickup
to the ACCEL INPUT jack (BNC connector), at the rear of the rack.

Digital Panel Meter

The DPM is a 3-1/2 digit meter t hat monit ors the input level. It has t hree rang es:
10, 100, or 1000 units, and a switch to select either Acceleration g’s, Velocity
IPS, or Displacement MILS.

If 230 V Power is appli ed when this sw i tch is set for

115 V RMS, circuitry will be dam aged.

Units Switch

The UNITS switch selec ts g ’s, IPS, or MILS as the UNITS to be displayed on the
front panel meter and at the DC O UT PUT jack.

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203M User Manual Publication No. 980978 Rev. A

METER RANGE Switch

The METER RANGE Switch has three positions to select: 10, 100, or 1000 units
full scale. The DC OUTPUT is 10 Volts f ull scale for each range

Sensitivity (RANGE) 1-11 or 10-110 Switch

The two-position SENSITIVITY Switch is a range selector for the variable
sensitivity control. The proper range selection and sensitivity control setting
allows using pickups from 1 to 110 pC/g or mV/g sensitivities. Place this switch
to the range the pickup sensitivity falls in. For instance, if the pickup is 20 pC/g ,
the 10 to 110 range is selected.

SENSITIVITY Cont rol

The sensitivity control is a calibrated ten-turn potentiometer to provide a
continuously variable sensitivity for each range selected by the SENSITIVITY
RANGE switch. For the above example, the control will be set for 2.0

SE-DIFF Swi t c h

This switch permits selection of a single-ended input (SE) or Differential Input
(DIFF). W hen the DIFF position is selected, the common mode rejection can be
adjusted by the DIFF ADJ control, a screwdriver adjust ment immediately below
the DIFF position of the switch. If operating with a pickup that is insulated (no
ground) the single-ended (SE) position should be used. When the pickup
common is grounded, the Differential (DIFF) input opens the ground path
between the pickups and the amplifier and provides rejection of the common
mode voltage.

OPER-CAL Switch

The OPER-CAL switch selects either the ACCEL input when in OPER, or the
internal calibrator input when in the CAL position. The internal calibrator level
can be monitored at the CALIBRATION INPUT BNC connector just below the
OPER-CAL switch. When the OPER-CAL switch is in the OPER position, the
calibrate mode can be selected from a rem ote CAL CONTROL line. When the
CAL mode is selected, either by the front panel switch or t he remote CAL CONT
line, the CAL LIGHT just to the right of the switch illuminates, and the meter
should read 100 ±3 g’s or 100 ±5 MILS.

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MV/g Output Switch

This switch sets the normalized sensitivity at the ACCEL OUTPUT. Either 10
mV/g or 100 mV/g can be selected. This switch setting does not affect the
sensitivity at the displacement output.

LP FILTER Switch

The Low Pass Filter (LP FILTER) switch has three posit ions mark ed LOW, MED,
and HIGH. Nominal frequency cutoffs of 3, 10, or 30 kHz are selected. The
cutoffs can be altered if different cut offs are more appropr iat e.

HOLD Circuit

The HOLD circuit has a center OFF switch with a momentary READ and ERASE
position. The HOLD circuit stores the hig hes t TRMS value encountered during a
test, and this value can be displayed on the meter by depressing the momentary
READ position of the switch. The HOLD circuit can be restor ed t o zero by
depressing the switch to momentary ERASE.

ALARM Circuit

The ALARM circuit has a SET switch, a light, and a SET ADJ control associated
with it. When the SET switch (momentary) is depressed, the SET ADJUST is
connected to the meter to indicate what level the alarm is set for. While the
switch is depressed, the alarm levels can be changed by varying the screwdriver
adjustment and noting the new value on the front panel m eter. W hen released,
the alarm is reset, the light is out, and it will remain thus until a level is
encountered which is higher than the ALARM SET level. When this level is
encountered, the ALARM light will illuminate and the alarm relay will be
energized. The contacts of t he alarm relay are on a terminal strip on the rear
panel. It should be noted that the alarm level is interconnected through the
METER RANGE switch. For instance, if 8 g’s is set on the 10 g’s range, it will
become 80 g’s if the 100 g range is selected.

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203M User Manual Publication No. 980978 Rev. A

RMS-PEAK Switch

The RMS-PEAK switch provides a means of scaling the meter circuit to read in
either PEAK or RMS units. W hen the input to the unit is sinusoidal, it may be
desirable to use peak g’s. When the input is r andom noise, the RMS position
scale the meter to read RMS units, and because the detector is a true RMS
converter, it will read either sinusoidal or random inputs correct in RMS units.

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Chapter 3

Performance Test

This procedure outlines a method of testing the Charge Amplifier f or compliance
to the manufacturer’s specifications. The unit uses integrated circuits and very
stable parts and should not require calibrat ion more often than every six months.
The amplifier may be in a single-unit cabinet or one that holds six units. The
following procedure is for a single unit, and must be repeated f or each module. In
the event that a reading is out of tolerance t he unit will require calibration. (See
Chapter 4.)

Test Equipment

Note: Equivalent equipment can be substituted.

Multimeter Fluke 8000A
Generators (2) Trig-Tek 346B Synthesized Calibrator.

Performance Test Procedure

The 115-230 VAC switch (S1, mounted on the unit’s circuit boar d) must

be at the proper setting. If 230 V Pow er i s appl ied when this switch is set for

115 V RMS, circuitry will be damaged.

Check the unit to be tested for any loose or broken wires or signs of damage
caused by rough handling or dropping. W hile the unit is out of the chassis, check
S1, the 110-220 switch, is set for 110 if 105 t o 120 Volts is to be used, and for 220
if 210 to 230 Volts is to be used. The unit will be damaged if plugged int o 220
VAC power when set up for 110 VAC operations.

Plug the unit into the chassis and turn the POW ER Switch ON; this is a single
switch at the left side of the chassis. The meter displays, and the POWER LED
will illuminate.

CAUTION

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203M User Manual Publication No. 980978 Rev. A

Control Settings

Place the CAL-OPER switch to OPER, the SENSITIVITY switch to 1-11, the
SENSITIVITY DIAL to 10.0, the PEAK-RMS switch to RMS, the UNITS switch to
g’s, the FULL SCALE switch to 100, the INPUT switch to pC/g, the SE-DIFF
switch to SE, the OUTPUT mV/g switch to 10, and the LP FILTER SWITCH to
MED.

1. Connect a 139.9 ±0.5 Hz signal set for 707 ±4 millivolts RMS from t h e
PICOCOULOMB Output to the ACCEL INPUT jac k at the rear of the
chassis.

2. Connect the AC Voltmeter to the NOR ACCEL OUTPUT j ack on the rear
panel.

3. The indications on the Voltmeter should be 707 ±20 m illivolts, and the front
panel meter will indicate 70.7 ±2 g’s.

4. Place the PEAK-RMS switch to PEAK.

5. The front panel meter will indicate 100 ±3 g’s.

6. Place the OUTPUT mV/g switch to 100.

7. The indication on the AC Voltmeter will be 10x the previous reading or

7.07 ±0.2 Volt.

8. Place the OUTPUT mV/g switch to 10. Set the SENSITIVITY DIAL for 1.0
and the FULL SCALE switch to 1000.

9. The indication on the front panel will be 1000 ±30 g’s.

10. Place the SENSITIVITY switch to 10-110, and the FULL SCALE switch to

100.

11. The indication on the front panel meter will be 100 ±3 g’s.

12. Place the SENSITIVITY switch to 1-11, and the DIAL to 10.0.

13. Connect the DC Voltmeter to the DC OUTPUT jack.

14. The indication on the DC Voltmeter will be 10.00 ±0.3 Volt.

15. Connect the AC Voltmeter to the VELOCITY OUTPUT jack and place the
UNITS to IPS. Set the generator frequency for 61.4 ± 0.2 Hz.

16. The indication on the AC Voltmeter will be 0.707 ±0.02 VRMS, and the
front panel will indicate 100 ±3 IPS

17. Connect the AC Voltmeter to the DISPLACEMENT OUTPUT jack, and
place the UNITS switch to MILS. Set the generator frequency for 139.9
±0.5 Hz.

18. The indication on the AC Voltmeter will be 0.707 ±0.02 VRMS, and the
front panel will indicate 100 ±3 MILS.

19. Place the UNITS switch to g’s, depress the ALARM SET switch, and set
the ALARM adjust for an indication of 93 g’s.

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20. When the ALARM SET switch is released, the ALARM LIGHT will
illuminate and the ALARM RELAY will energize. (Rear panel terminal
strip).

21. Depress the ALARM SET switch and set the alarm level for 105 g’s.

22. Release the ALARM SET switch; and ALARM will not come on.

23. The Low Pass filter cutoffs nominally have 3, 10, and 30 kHz 20% of
frequency, -3dB bandwidths for t he LOW, MED and HIGH LP Filter switch
positions. Other cutoff frequencies are available, so determ ine t he ac t ual
cutoffs bef or e t es t ing.

24. Place the LP FILTER switch to LOW.

25. Increase the generator frequency until the m et er indicates 70.7 ±9 g’s.
The frequency of t he signal generator is the –3dB cutoff for the LP
FILTER.

26. Place the LP FILTER switch to MED.

27. Increase the generator frequency until the m et er again indicates

70.7 ±9 g’s, the –3dB cutoff of the MED low pass filter.

28. Place the LP FILTER switch to HIGH.

29. Increase the generator frequency until the m et er again indicates

70.7 ±9 g’s, the –3dB cutoff of the HIGH low pass filter .

30. Connect the counter and AC voltmeter to the CAL INPUT jack on the front
panel.

31. Place the CAL-OPER switch to CAL.

32. The counter indication will be 139.9 ±0.8 Hz and the AC voltmeter will
indicate 1.00 ±0.01 Volt RMS.

33. The front panel meter will indicate 100 ±3 g’s.

34. Vary the SENSITIVITY DIAL f rom 1-11; observe that the front panel meter
indication changes less than 1 g for any sett ing.

35. Place the SENSITIVITY switch to 10-110. The meter indication will remain
100 ±3 g’s.

36. Place the UNITS switch to MILS. The meter will indicate 100 ±3 MILS.

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Chapter 4

Calibration Procedure

The 203M Charge Amplifier is a plug-in module with the circuitry on a single,
printed board. To calibrate, rem ove the module and use the Module Power Cord
Assembly TT-1535 to apply power and Board Test Assembly TT-1536 to provide
an interface or monitoring. For adjustment locations refer to Figure 4-1 and

Figure 4-2.

Test Equipment

Note: Equivalent equipment can be substituted.

Multimeter Fluke 8000A
Counter Fluke 1900A

Function Generator Trig-Tek 346B Synthesized Calibrator

Power Cord Assembly Trig-Tek TT-1535.
Board Test Assembly Trig-Tek TT-1536.

Switch Settings

1. Place the CALIB-OPER switch to OPER, the SENSITIVITY switch to 10-110,
the mV/g-pC/g switch to pC/g , the SE-DIFF to SE, the UNITS switch to g’s, t he
FULL SCALE switch to 1000, the PEAK-RMS switch to PEAK, the LP FI LTER
switch to HIGH, and the output mV/g s witch to 10.

2. Turn the DIAL to 10.

3. Place the module to be tested on the bench, and plug the Charge Amplifier
Assembly TT-1536 into the printed circuit board connector at the rear of the
module and the Power Cord Assy. 1535 to the power receptacle.

4. Connect to 50 to 400 Hz, 110 or 220 Volt power.

5. Set the 110-220 switch, S1, as required to accom m odat e the power used.

Astronics Test Systems Calibration Procedure 4-1

203M User Manual Publication No. 980978 Rev. A

Charge Converter and Displacement Adjust

1. Set the Dial to 10.0

2. Place the SENSITIVITY Switch to 10-110 and the CALIB-OPER switch to
OPER.

3. Connect the AC Voltmeter to Pin 8 of P1 (ACCEL OUTPUT of the Test Board).

4. Connect a 61.4 ±0.1 Hz signal to the ACCEL INPUT jack on the Test Board
and set it for 7.07 ±0.04 Volts RMS.

5. Set the ACCEL ADJ R8 for a 707 ±4 millivolts RMS indication on the AC
Voltmeter.

6. Set the Dial for 1.0.

7. Set the DIAL ADJ R1 for a 7.07 ±0.04 Volts RMS indication on the AC
voltmeter.

8. Connect the AC voltmeter to Pin 10 of P1 (VEL OUTPUT of the Connector
Board Assembly).

9. Set the VEL FS ADJ R7 for a 7.07 ±0.07 Volt RMS indication on the AC
Voltmeter.

10. Connect the AC Voltmeter to the DISPL OUTPUT, Pin 11 of P1 of the Test
Board, and set the input frequency for 139.9 ±0.3 Hz.

11. Set the DISPL FS ADJ R4 for a 7.07 ±0.07 Volt RMS indication on the AC
Voltmeter.

DVM Adjustments

1. Place the SENSITIVITY Switch to 1-11, the Dial to 10.0, t he CALIB-OER
switch to OPER.

2. Connect the DC Voltmeter to Pin 13 of P1, DC OUT PUT of the Test Board.

3. Connect a 7.07 ±0.04 Volt signal of 139.9 ±0.5 Hz to Pin 17 of P1, the ACCEL
INPUT of the Test Board.

4. Observe a 10.00 ±0.05 Volt indication on the DC Voltmeter.

5. Set the DVM FS AJ R1 (Figure 4-2) on the front panel meter as sem bly f or a
1000 ±8 counts on the front panel m et er . (Adjust the resistor through the hole
on front panel board.)

Calibration Procedure 4-2 Astronics Test Systems

Publication No. 980978 Rev. A 203M User Manual

R8
R1

R2

DVM

Adjustment

R9

R4

R7

S2

Calibrator Adjustments

1. Place the CALIB-OPER switch to CALIB. (The CALIB light should illuminate.)

2. Connect the counter and Voltmeter to t he CALIBRAT OR OUTPUT BNC on the
front panel.

3. Observe a 139.9 ±0.4 Hz indication on the counter.

4. Set the 1 Volt front panel LEVEL ADJ for a 1. 000 ±0.005 Volt RMS indication
on the Voltmeter. (The front panel LEVEL ADJ screw will need to be removed
if adjustment is necessary).

5. Place the sensitivity switch to 1-11, the Dial to 10.0, the FULL SCALE switch to
100, and the PEAK-RMS switch to PEAK.

6. Set the CAL ADJUST R9 for 100.0 ±0.8 g ’s count s indication on t he front
panel meter.

7. Set the Dial for 1.00.

8. Set the DIAL CAL ADJ R2 for a 100.0 ±0.8 g ’s count s indication on t he front
panel meter.

Astronics Test Systems Calibration Procedure 4-3

Figure 4-1, 203M Adjustment Locations

203M User Manual Publication No. 980978 Rev. A

Figure 4-2, DVM Adjustment Resistor R1

(Adjust R1 though h o le in board)

Calibration Procedure 4-4 Astronics Test Systems