Application Note 40 - Solving Sensor Problems

Application Note 40 - Solving Sensor Problems

Sensors have been with us ever since the days when Watt invented the flyball governor for steam engine speed regulation. While we are seeing an increase in optically-encoded outputs suitable for optical-fiber cable use, most sensors we encounter today use electrical signals to transmit their output back to the controlling device With the increase in microprocessor-controlled signal processing the signal levels in the wiring harnesses have generally dropped to TTL/MOS levels, that is, voltage under 5 volts and with correspondingly low currents.

Unfortunately for the reliability of equipment whose operation is controlled by sensors, connector reliability at these voltage sorts and power levels has lagged behind the demands placed upon them and the consequences are, for example, that it is estimated that 10% of all automobiles stalled on the roadside are suffering from a electrical connector failure of some sort.

The same conditions exist in many other areas, be it untimely landing-gear retraction caused by "squat-switch" failure to unnecessary rejections of IC's during the final acceptance tests caused by improperly functioning test fixture connectors.

Where "sensor-failures" occur, the lost-of-time and loss-of-product can be expensive The cost of replacing perfectly-good sensors because of the malfunction of a connector (whose cost is generally only a fraction of the cost of the sensor itself) can really hit a service group in the pocketbook. Normally, reimbursement of the service group for labor and parts costs are dependent upon testing by the manufacturer to verify that the assembly is actually at-fault. The problem is that a simple disconnect an reconnect cycle will usually clear up the connector problem (for a short time anyway) and thus the faulty connector may perform flawlessly under the manufacturer's testing conditions. Not only is the customer annoyed by the original down time, but the service group is out-of-pocket. Another problem is the potential for loss of good relations between the dealer and customer, and between the manufacturer an dealer.

Often the long-term duty cycle of the equipment can increase the problem. For example, in the agricultural implement field, the situation can be aggravated by the that the equipment is usually laid-up for the major part of the year and then is called upon to function perfectly during several weeks of intensive use. It is not unusual f farmers to run their combines on a multiple-shift basis to bring in the crop as soon a the grain ripens, thus any worst-case down-time can increase the potential for major financial loss to the farmer due to adverse weather conditions.

Can Sensor-Connector Problems be Reduced?
Yes, the Stabilants have proven to be very effective in improving the reliability of connectors in general and are developing a reputation for ease and speed of use under field conditions. Not only are many OEM's pre-treating sensor connectors during manufacture, many are providing the Stabilants to their service technicians either as Standard Store items, or recommending them for field procurement.

The Stabilants are presently used in applications ranging from Avionics through Process control, including such critical fields as Bio-medical electronics, Air-Traffic Control, Police & Emergency communications and the like.

How are the Stabilants applied?
The application of the Stabilants is exceptionally easy. Just use a drop of two of Stabilant 22A, for example, on one of the sensor connectors and any other in-signal-path connector in the wiring harness, and reconnect the system.

Not only are they are easy to use but they have so many potential applications in industry, automotive, farm and even in the home (on everything from Computers, to CATV, and Stereo Systems) that they should be in everyone's tool-kit!

Revision 1

Stabilants™ are a product of Dayton Wright research & development and are made in Canada

NATO Supply Code 38948
15 ml of S22A has NATO Part # 5999-21-900-6937