Selection of Output

An array of output options is available. Your choice depends on whether the sensor is used in conjunction with a controller, or is a stand-alone unit. If using a controller, make sure it can handle the output offered by the sensor manufacturer.

Stand-alone sensors, such as a digital pressure gauge, usually come with a visual display, but can also include an electrical output, and can still be used in conjunction with a controller.

Again, match the output of the sensor to the input requirements of the controller.

Selection of Accuracy

While price is not actually one of the considerations addressed in this article, accuracy is perhaps the key factor in driving the cost of a pressure transmitter. The higher the accuracy required, the higher the cost. By carefully examining what accuracy is required for the application, you are, in fact, limiting the expense of your project.

After defining the accuracy needs of the application, you must ensure that you understand how your accuracy calculation method matches up with how the prospective supplier calls it out on a datasheet.

For example, if you are calculating using a straight-line or terminal end-point method, it is not the same as a best-fit-straight-line (BFSL) method. In addition, some manufacturers combine linear performance, hysteresis, and repeat ability in the accuracy specification while others call them out separately.

I am not advocating one method over the other; just make sure you understand how the sensor specification matches up with your requirement.