Our pressure transmitters, also known as pressure transducers, use piezoresistive technology to accurately measure pressure. This is based off of a small circuit called a Wheatstone bridge attached to the back of a diaphragm. As the diaphragm flexes from pressure, the resistance in the Wheatstone bridge (hereafter known as the “sensing element”) changes relative to pressure, providing a basis of measurement.
There are a few different methods of mounting the sensing element to the pressure transmitter diaphragm. Each has it’s own set of pros and cons. For example, some perform better in low pressure environments, others in high pressure. We’ll use the best method according to the configuration of your sensor.
Once the measurement is taken, the transmitter conditions the signal to the output you have chosen and sends it off to your control system.
While we only list a few pressure transducer families, each has a wide variety of configurable options when you purchase. These include options for:
Most allow you to adjust the zero and span in the field as well.
APG pressure transmitters are used throughout industry, in both process and storage environments. Our PT-L families are built for industrial applications in pressure ranges up to 10,000 psi, and are suitable for both liquids and gasses. They are designed to provide accurate measurements and a long life expectancy at a low cost.
Our PT-400 family is designed for extreme environments. In particular, our heavy duty pressure transducers are designed to handle:
They’re popular in the Oil & Gas industry where demanding conditions are further complicated by hazardous classified areas. In particular, our PT-400 pressure transmitters are well suited for applications with extreme vibration - where other pressure transducers tend to fall apart.
Yes. Our popular PT-400 model is commonly used in outdoor locations such as lift stations, oil rigs, and tank farms, and has built-in reverse polarity and surge protection compliant with IEC 61000-4-5. Our standard duty models are meant for indoor environments and do not have lightning protection.back to top
Yes. The PT-400 is designed for outdoor use in harsh and hazardous conditions. It's hazardous location certifications include CSA Class 1, Div. 1, ATEX, and IECEx approvals for worldwide use. It's also built to withstand intense vibration common on oil rigs.back to top
We have two varieties of simple pressure transducers. Our PT-L9/13/14 series have a non-amplified mV/V output, is super compact, inexpensive, and great for anywhere you won't have a lot of electrical noise. Our PT-L1/L3/L10 series has an amplified output (VDC & 4-20mA), is compact, still inexpensive, and works better where electrical noise is more of a concern.
These models aren't beefed up for extremes like our larger PT-400, but they're just as reliable in controlled environments and often trusted in critical applications.back to top
Different sensing elements have different pros and cons. The pros of a MEMs transducer is that it's more stable and costs less. However, strain gages and foil gages have their own set of pros that make them preferable in the right circumstances. Rest assured, we use whichever type of transducer that is most suitable for your application.back to top
We recommend having your pressure sensor calibrated at least once per year, or annually. However, most ISO 9001 compliant maintenance schedules are adequate. If you ever start to question your sensor's accuracy, have it calibrated. We can calibrate any of our own sensors. Contact us for a quote.back to top
In general, the overpressure rating is 1.5X full scale range. But this changes based on the configuration and pressure range of your sensor. The higher the pressure range, the less overpressure you can get away with. Burst pressure is another important spec. This depends on the yield strength of the material used to make your pressure diaphragm. Consult with us on your specific model for more detail.back to top