Copyright 2011 by Astronics Test Systems Inc. Printed in the United States of Amer ica. All rights reserved.
This book or parts thereof may not be reproduced in any form without written permission of the publisher.
For this product, or any other Astr onics Test Systems product 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:
All Astronics Test Systems products are desig ned to exacting standards and manufactured in full
compliance to our AS9100 Quality Management System processes.
This warranty does not apply to defects resulting f rom 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 mechanical r elay lif e, 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 Cust omer Support. Please have the
following information available to facilitate service.
Authorization is required from Astronics Test Systems before you send us your product or sub-assem bly 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 Systems.
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.
Before undertaking any troubleshooting, maintenance or exploratory procedure, read carefully the
WARNINGS and CAUTION notices.
This equipment contains voltage hazardous to
human life and safety, and is capable of
If this instrument is to be powered from the AC line (mains) through an autotransformer,
ensure the common connector is connected to the neutral (earth pole) of the power
supply.
Before operating the unit, ensure the conductor (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 protective feature of the third
conductor in the power cord.
inflicting personal injury.
Maintenance and calibration procedures sometimes call for operation of the unit with
power applied and protective covers removed. Read the procedures 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 prox imity 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.
Power ............................................................................................................................................. 1-3
The 850A/B Contact Chatter Detector (Figures 1-1 and 1-2) is designed to
provide a means of monitoring the continuity of switch or relay contacts while
being subjected to environmental stress. The unit has 10 channels each with a
separate current source to activate the contacts. Contact current dial and X1–
X0.1 switch sets the current of all the channels simultaneously for 0.1 to 11
milliamps.
The difference between the two models is that the 850A uses BNCs for the
channel inputs and the 850B uses screw terminals.
Timing Interval Controls provide for setting from 1 to 999 microseconds or 1
999 milliseconds for the maximum time a discontinuity can exist. Each channel
has a FAULT LED which will illuminate if a discontinuity exists for a long er period
of time than is set in by the Timing Interval Switch. The LED will remain
illuminated until reset either by the front panel reset switch or remotely via a reset
terminal. The unit has a terminal strip where the FAULT condition of each channel
can be recorded Low "NO FAULT" o r HIGH "FAULT."
Either Normally Closed (NC) or Normally Open (NO) contacts can be monitored.
A toggle switch on each channel permits selection of NC or NO type contacts.
Specifications
Controls
Channel Inputs (10 each)
Current Source Compliance 3 Volt (maximum).
Current Source Accuracy ±3% FS.
Timing Interval Accuracy Setting ±5 LSB.
Fault Reset Terminal Permits FAULT Reset from r em ote location.
The 850A/B Contact Chatter Detector contains t en contact monitors in a chassis
19 inches wide by 3-1/2 inches high and 8 inches deep.
The unit operates using either 117 or 234 Volts RMS power. The switch S1 next
to the transformer (cover must be removed to view, see Figure 2-1) is mark ed 117
and 234. Set S1 to the appropriate pos ition for the power that is to be used.
Damage can be caus ed to the circuit ry if S1 is in the 117 posit ion and 234 V RMS
AC power is applied. With S1 set properly, apply the AC power and the unit is
ready to operate.
Current Setting
Before connecting any contact to the Contact Chatter Detector, set the current
that will flow in the contact. Damage could be caused if the current was set higher
than the contact current rating. The current is set between 0.1 to 11 millliamps
using the contact current dial and the X1–X0.1 switch to provide two ranges.
When the X 1–X0.1 switch is in the X0.1 position the dial sets 0. 1 to 1.1 milliamps
and the X1 position provides 1 to 11 milliamps. The current setting is for all ten
channels. To prevent damage to the contacts each channel voltage is clamped
below 3 Volts.
Time Interval Switch Settings
The Time Interval Switches set the time discontinuity can exist (in a NC contact)
before it is considered a FAULT, for a NO contact the opposite or closure for
longer than the set time interval would constitute a FAULT. T he time interval can
be set from 1 to 999 microseconds or 1 to 999 milliseconds using t he three digit
thumb switch in conjunction with the MICROSEC-MILLISEC switch. T he accur acy
is the setting ±3 LSD. These switches should be set to the appropriate setting for
the contact or contacts being m onit or ed.
Contact Connections and Switches
Connect the contact to be monitored to a channel input BNC (850A) or terminal
(850B). Set the Contact Switch to the required position NC if the contact is in the
closed position and NO if the contact is being t ested in the open position.
When a NC (Normally Closed) contact has a discontinuity longer than the set in
time interval, it is a FAULT, for NO (Normally Open) contact continuit y for a period
longer than the set in t ime interval constitutes a fault. When a FAULT is detected
the FAULT LED for that channel illuminates and a +12 V signal is present on the
FAULT output terminal on the rear panel. To remove the f ault the FAULT RESET
switch should be depressed, this removes the fault from all channels. The FAULT
RESET can be accomplished remotely by applying +12 volts to the RESET
terminal on the rear panel.
The circuitry of the 850A/B Contact Chatter Detector is stable and should require
calibration only in the case of part failure. Astronics Test Systems recommends a
12-month calibration period or longer.
Refer to Figure 3-1 for both calibration adjustments. Remove top cover of the
850A/B to access components.
Timing Interval Adjustment
1. Connect a frequency counter to Pin 3 of U3 (Figure 3-1).
2. Set the MICROSEC-MILLISEC Switch to MICROSEC.
3. Set the timing adjust R33 f or an indicat ion of 1 MHZ ±10 kHz.
4. Place the MICROSEC-MILLISEC switch to MILLISEC.