- Pressure Transmitters


How Do You Select a Pressure Transmitter?

The two areas of focus when selecting a pressure transmitter are the operating conditions (environment) and performance requirements. Environmental information allows for the selection of an appropriately rugged pressure transmitter able to withstand the media and operating /ambient temperatures. Knowing the specific performance requirements allows a pressure transmitter to be specified that can handle the system’s pressure at the desired accuracy.


Knowing where the transmitter will be operating and choosing accordingly the transmitter case and wetted materials will extend its service life. Each transmitter should be selected partly on the basis of the medium being measured. Ensure that the parts exposed to the medium are compatible with or can withstand its particular characteristics.

Keep in mind that heavy vibration, shock, moisture and electric interference will affect pressure sensing. Since each application is specific to a certain set of requirements, understanding the application’s needs will determine the model required.

Extreme temperature ranges can also produce adverse effects to reading accuracy. Make sure you identify an acceptable temperature effect on span (thermal drift) when selecting your transmitter. These can be as low as 0.2% FSO per 10°K.

If the transmitter is installed for outdoor use, ensure that the appropriate type of enclosure/seal is selected. All of Winters’ pressure transmitters are sealed against water and dust entry, and meet standard NEMA enclosure ratings. Standard housings are 304 or 316 series stainless steel.


Is the pressure range being measured in the positive or vacuum scale of measurement? Is each point of measurement stand-alone or are the differences between two points being measured (differential)?

In general, pressure transmitters provide highly accurate pressure readings. It is important, however, to always choose a range that is suitable to your requirements. Consider this scenario: a transmitter that has an operating range of 0 to 200 psi and has an accuracy of ±0.25% is being used to measure pressure on a piece of equipment that only goes to a maximum of 20 psi. An accuracy of ±0.25% over a 200 psi range means that the maximum error you may see is ±0.5 psi. Therefore, for a measurement output of 7 psi, the real number may be between 6.75 to 7.25psi. An error of 0.5 psi means you have selected a transmitter with an error of 7.14% (0.05 divided by 7) at 7 psi. So, select a transmitter that has the closest normal operating range to what you are measuring, and consider an acceptable accuracy percentage.

Also, be sure about the type of output you need. Winters’ standard transmitter outputs are in milliamps. Output in volts is available.


Transmitters can be thought of as electronic pressure gauges. There are two kinds of electronic pressure gauges: pressure transmitters and pressure transducers. The general difference between a transmitter and transducer is the electrical output, where a transmitter outputs signals in milliamps (mA) and a transducer outputs signals in volts (V) or millivolts per volts (mV/V).

Power is supplied to the circuit.

  1. Pressure pushes on a sensor
  2. The sensor flexes and changes the resistance or capacitance of a circuit mounted on the backside of the diaphragm (the change in the flow of electricity across the circuit is in direct proportion to mechanical force/pressure applied to the diaphragm)
  3. Special electronic circuitry conditions amplify the sensor’s signal and converts (transducers) it to a useable signal (i.e. 4-20 mA)
  4. Electrical output signal is sent to an indicator or computer

Note: When selecting a pressure switch, always refer to CAN/CSA-C22.2 NO. 61010-1-12 – Safety requirements for electrical equipment for measurement, control, and laboratory use – Part 1: General requirements (Tri-national standard), with UL 61010-1 and ANSI/ISA-61010-1 (82.02.01)

Order Codes:


WINSMART™ LY16 SMART Explosion Pressure Transmitter

WINSMART™ LY36 SMART Explosion Proof Pressure Transmitter

LE1 OEM Transmitter

LE3 General Purpose Transmitter

LIM Aggressive Media Transmitter

LIS Intrinsically Safe Transmitter

LLP Low Pressure Transmitter

LM1 Anti-Clogging Submersible Transmitter

LM3 Slim Line All-Purpose Submersible Transmitter

LM6 All Stainless Steel Submersible Transmitter

LM7 General Purpose Submersible Transmitter

LMH Hydraulic Transmitter

LOH Well Service Transmitter

LST 3A Sanitary Transmitter

LTD Differential Transmitter

LTF Flush Mount Transmitter

LXP Explosion Proof Transmitter


Disclaimer: The content of these pages and documents are to be used for information purposes only. While Winters has taken every necessary step to verify the accuracy of the content, Winters cannot be held responsible or liable for any damages resulting from its use. We recommend speaking with a Winters representative if you have questions about selecting a product. Winters reserves the right to make product improvements that may not be reected here. All content is property of Winters and cannot be used without permission.

- Pressure Transmitters

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