Knowing the risk to human lives and the financial costs when things malfunction, aerospace engineering and manufacturing processes require total precision. The application of sensors during preparation and flight help to guarantee accuracy by gathering vital information that can proactively detect issues.
Earlier, most sensors used in aerospace and space engineering were tailor-made and tested for each application. With an uptick in the commercial space market, there is a growing trend of using off-the-shelf sensors whenever possible to reduce cost and speed time-to-market. However, an off-the-shelf solution is not always the ideal choice. Sometimes an altered or custom-built sensor not only offers more accuracy, but can also be less expensive and faster to implement.
This article focuses on what customers need to know to make the right choice for their specific circumstances.
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When Off-the-Shelf Sensors Work Best
- Geometry – The sensor needs to be the right shape and size to suit specific needs.
- Connectivity – The sensor should connect easily to data loggers and other data acquisition and control equipment.
- Measurement range – The sensor needs to be built to handle the appropriate range of measurement, whether it is pressure, temperature, humidity, flow or another measurement.
If a typical sensor can meet all three of these criteria for a particular application, then an off-the-shelf product is the best option for minimizing delays and keeping accuracy high.
The Modification Myth
For aerospace customers who find there is not a typical product that meets all three criteria, the next step is usually to consider altering an off-the-shelf sensor. This requires choosing a sensor that will continue to work for users’ application with slight modifications, such as tweaking the length, diameter, or by finding another way to mount the sensor. The idea being that altering an off-the-shelf sensor will still be quicker and less expensive than having it tailored.
The reality is that in-house alteration is not always less expensive or quicker—and could result in lower accuracy. To find out if alteration is the right approach, the following will need to be evaluated:
- How long it will take to make the necessary modifications
- Whether it is the highest value/best use of those skilled resources
- What is your in-house resource capacity to make those alterations
- The success/failure rates during testing
- The total cost of modifications
At times these answers are initially hard to ascertain. For instance, one Aerospace Manufacturer opted to alter off-the-shelf RTD sensors by developing and assembling its own housing for the sensors. It was only after the in-house assembly that the manufacturer discovered that a high percentage of their RTDs were failing to function as anticipated. This resulted in low yield, testing, rework and delays that caused an increase in costs and lengthened timelines.
The Added Value of Customization
According to the latest research by Deloitte, the commercial aerospace market continues to experience substantial schedule delays ranging from two to four years.
With costly aerospace programs on the line, even minor delays, such as having to redesign or rework the sensor housing to enhance accuracy can end up being very costly—but customization can help prevent these types of impacts. For instance, the Aerospace Manufacturer who began with an in-house modification of common RTD sensors found out that customization not only accelerated time-to-market, but lowered costs and provided more accurate readings.
The value of customization keeping timelines on-track is particularly true when there is a delay in the design or development procedure; it becomes apparent that a common sensor will not function for the particular application. Designing, constructing, assembling and testing an altered solution in-house is likely to take substantial resources and time away from the project at a crucial stage.
Performance also increases when the housing is tailored because it can be customized to the size and shape required for the sensor to function most efficiently in the entire process. One of the major benefits for the Aerospace Manufacturer, who switched from in-house modifications to have the sensor made-to-order, was the resulting robustness of the product, which went from high failure rates to 100% tested and ready-to-use.
Conclusion
Off-the-shelf sensors have their purpose and can be a good value when they match all three criteria—measurement range, geometry and connectivity—for ideal performance. However, in situations where a basic product requires alteration, a modified, turnkey solution that includes the manufacturing, assembling, testing and shipping with a typical sensor may prove to be the right choice. Aerospace Engineers and Manufacturers not only acquire sensors enhanced for their application, but can also save high-cost resources for where they will be most useful—innovating and engineering new aerospace processes and products.
This information has been sourced, reviewed and adapted from materials provided by OMEGA Engineering Ltd.
For more information on this source, please visit OMEGA Engineering Ltd.