Position Measurement & Control - August 2000 (S050-2)

Contents

• DO-160D Aircraft Environmental Testing
• Application Corner
  • Suction Cup Mounts
  • New Display Meters Offered
  • Returning Products to Firstmark Controls
  • Educational Transducer Program
• In Action
  • Almond Processing Equipment
  • Mayonnaise Production Mixing
  • Child Dummy Thorax Measurement
  • Black Boxes for Long Haul Trucks

DO-160D Aircraft Environmental Testing

Firstmark Controls products have been used in aircraft flight data recorder ("black box") applications for over 4 years. Currently, a comprehensive suite of environmental tests are being conducted on a range of Firstmark Controls products to verify the suitability for extended aircraft use, both inside and outside the aircraft pressure vessel. This test suite, performed according to DO-160D (Environmental Conditions and Test Procedures for Airborne Equipment), has passed the midway completion point.

The testing gives airlines, systems integrators, avionics firms, and related organizations test data to use in the design of aircraft sensor systems for flight data recorder, flight test, aircraft modification, and similar uses.

After the Waterproofness Test: position transducers shown on test fixture and attached to the actuating mechanism.

Position transducers being readied for the Fluids Susceptibility Test.

A set of 5 position transducers are being tested including a Series 150, Series 174, and 3 Series 160 products in different configurations. For the tests, the products are mounted to a 1-inch thick aluminum plate and actuated by an electrical motor attached to a drive shaft via a universal joint.

The test suite is being conducted at Garwood Laboratories, Inc. of Pico Rivera, California over a 90-day period. Garwood Laboratories is an ISO 9002-registered and A2LA accredited (ISO Guide 25) test facility. Over 1200 man-hours have gone into the development and implementation of the test suite. Development activities included in-house production of test fixtures, actuation devices, and data acquisition systems.

Published by RTCA, Inc., DO-160D has standard procedures and environmental test criteria for testing airborne equipment for the entire spectrum of aircraft from light general aviation aircraft and helicopters through the "Jumbo Jets" and SST categories of aircraft. The document includes 25 Sections and three Appendices. Examples of tests covered include vibration, waterproofness, fluids susceptibility, radio frequency susceptibility, temperature exposure, and explosive atmosphere. Coordinated with EUROCAE, RTCA/DO-160D and EUROCAE/ED-14D are identically worded. The tests are similar in scope and method to those described by other standards and standards organizations such as MIL-STD-810, NEMA, and ISO.

DO-160D is recognized by the International Organization for Standardization (ISO) as de facto international standard ISO-7137. For more information on DO-160D, contact RTCA (http://www.rtca.org).

For copies of the test suite, test reports, and test data summaries, please contact Firstmark Controls's Engineering Department at info@Firstmarkcontrols.com or complete our comments form. If you would like assistance in performing your own set of environmental tests on our position transducers, please contact us.

Garwood Laboratories, based in Pico Rivera, California USA, is ISO 9002-registered and A2LA accredited (ISO Guide 25). They have been involved in environmental testing for over 45 years.

Application Corner

The Application Corner is dedicated to answering your questions about using position transducers in specific applications. If you have an application question you would like answered, please let us know by phone, fax, e-mail, or mail.

Q. I need to temporarily mount your position transducer to a surface that cannot be marred or otherwise altered. Do you have any ideas on how to do this?

A. You may want to try suction cup mounts that are quite versatile in certain applications. A supplier of suction cup mounts and related equipment is Wood's PowrGrip Co., Inc. http://www.powrgrip.com

Q. We are looking for a complete measurement solution including a display device and power supply. Do you offer these items?

A. We now offer our 300430 (5-digit, 32776 positions) and 300431 (4-digit, 9999 positions) programmable, digital display meters providing flexible configuration; switchable 110/220 input; and a variable, regulated power supply. For a complete data sheet on these products, please visit our Literature Room

Q. We need to return a few items for calibration. How do we go about doing this?

A. If you need to return a product to us for any reason, please request an RMA (return material authorization) number from us before returning the product. By doing this, we can expedite the handling of your return. You can request an RMA number via our RMA Number Request form, phone, fax, or e-mail.

Q. Do you offer special pricing to colleges and universities?

A. We offer only one price list to all our customers. However, we do have an Eductional Transducer Program that allows students at colleges and universities to use our products in their projects at minimal cost. For more details on our program, please visit reqeduc.htm

In Action

Every month we see numerous fascinating applications of our position transducers. Here are a few recent ones:

Series 174 units are used to monitor up to 4 inches of movement on almond sorting mechanisms on processing equipment. The units measure the distance between roller arms and allow operators to precisely separate the arms based on the type of almond being processed. The electrical signal from the transducer is output to a programmable digital display.

Series 160 units are used to monitor mayonnaise production mixing equipment. Attached to the mixing angle actuator, the units provide feedback to a PLC.

Special subminiature position transducers with 0.5-inch-wide (13 mm) power springs are used to monitor thorax movement in child dummies. Ultra-small in size yet with high-g capabilities, these products help improve vehicle crash safety for children by measuring the effects of crashes on child dummies.

A set of Series 160 units are now being used on long haul trucks as a demonstration of the benefits of data recording in the trucking industry. Attached to "black boxes" (data acquistion systems), the position transducers monitor steering wheel movement and suspension movement in concert with other sensors to determine the symptoms and effects of driver fatigue.

ISSN 1527-5108