Digital Pressure Gauges - How They Work

Digital pressure gauges measure the pressure within a system in a special manner. They convert the pressure to an electronic signal. The gauge shows the pressure using a digital display, furthermore the signal can be used to control equipment. Digital gauges in comparison with analog ones have a higher accuracy. Read our article on analog pressure gauges if you want to learn more about that type.

Working principle

Digital pressure gauges make use of pressure sensors in order to convert pressure to an electronic signal. Different types of pressure sensors exist, but the most commonly used is a piezoresistive pressure sensor. This sensor consists out of a diaphragm that is equipped with piezoresistive elements. The medium pressure causes the diaphragm to deflect, this deflection causes a change in cross-sectional area of the piezoresistive elements that is directly coupled to the electrical resistance. For a more in depth explanation please read our article on electronic pressure measurement principles.

Why choose a digital over an analogue pressure gauge?

Next to a higher level of measurement accuracy digital pressure gauges offer options that are not available for analogue ones. A few examples of possible options are:

  • Backlighting: If pressure readouts are needed in dark conditions this options proves to be a great solution. Backlighting ensures that you are able to read the display in every lighting condition.
  • Min/Max values: This option provides better analysis of the set pressure in a system.
  • Bargraph display: The bargraph display shows the trend of the measured pressure. You can for example easily see if the pressure has an increasing, decreasing or steady trend.
  • Battery powered: This ensures that the pressure can be read in case of power outage.
  • Rotatability: Most digital pressure gauges allow for the display unit to be rotated to a large degree (e.g. 300°)

Read our selection tips for pressure gauges to learn more about this subject. For more information on various pressure gauges read our articles on bellows pressure gaugesdiaphragm pressure gauges, or bourdon tube pressure gauges

Digital pressure gauge accuracy

The accuracy of digital pressure gauges is expressed as a percentage of the measurement span. The accuracy of these gauges is combined from it’s non-linearity, hysteresis, End value deviation, zero offset and span error. For a detailed explanation please read our article on understanding pressure measurement accuracy.

Time : Aug 25, 2022
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Pressure Transmitters for Industrial Pressure Measurement

Xinyi Instrument supplies pressure transmitters for process control, hydraulic systems, petrochemical plants, water treatment, HVAC, power generation and general industrial pressure monitoring. Our pressure transmitter range covers gauge pressure, absolute pressure, differential pressure, high temperature media and digital communication applications.

Choose from compact pressure transmitters, smart 3051 differential pressure transmitters, diaphragm seal models, RS485 digital pressure transmitters and high frequency dynamic pressure sensors. Standard outputs include 4-20 mA, voltage output, HART and RS485 Modbus options, with stainless steel wetted parts and custom process connections available on request.

Pressure Transmitter Parameters

Pressure Types Gauge, absolute, negative pressure, differential pressure
Measuring Range From low differential pressure to high pressure ranges up to 100 MPa, depending on model
Output Signals 4-20 mA, 0-5 V, 1-5 V, 0-10 V, RS485 Modbus, HART options
Accuracy Typical options include 0.1%, 0.2%, 0.25% and 0.5% FS
Process Connection M20 x 1.5, G1/4, G1/2, NPT and customized thread connections
Wetted Materials Stainless steel, 316L diaphragm and corrosion-resistant sealing options
Media Water, oil, gas, air, steam and compatible liquid or gas media
Applications Pipeline pressure, tank level, flow differential pressure, hydraulic pressure and automation systems

Recommended Pressure Transmitter Series

  • Xinyi YW-150 - differential pressure transmitter for stable industrial measurement.
  • Xinyi YW-3051DP - smart differential pressure transmitter for process control.
  • Xinyi YW-130 / YW-140 - compact pressure transmitters for general pressure monitoring.
  • RS485 Digital Pressure Transmitter - Modbus communication for remote monitoring systems.
  • High Temperature Pressure Transmitter - designed for hot media and demanding process conditions.
  • Siemens, Yokogawa and ABB Options - international brand transmitters available for project matching.

Pressure Transmitter FAQ

What is a pressure transmitter used for?

A pressure transmitter converts the pressure of liquid, gas or steam into a standard electrical signal for PLC, DCS, recorder or control instrument input. It is widely used for pipeline pressure, tank level, flow measurement and process safety monitoring.

How do I choose the right pressure transmitter?

Confirm the pressure range, pressure type, medium, temperature, output signal, accuracy, installation thread, electrical connection and environmental requirements. For corrosive media, high temperature or sanitary applications, diaphragm material and sealing structure are especially important.

What is the difference between gauge, absolute and differential pressure transmitters?

Gauge pressure transmitters measure pressure relative to atmospheric pressure. Absolute pressure transmitters measure pressure relative to vacuum. Differential pressure transmitters measure the pressure difference between two points and are commonly used for flow, filter and level measurement.

Can Xinyi Instrument provide customized pressure transmitters?

Yes. Xinyi Instrument can support customized pressure ranges, process connections, output signals, cable length, display options and model selection for different industrial applications.