Many people struggle to distinguish between pressure sensors, pressure transducers, and pressure transmitters. However, these terms are often used interchangeably in the market. So, their differences are frequently overlooked.
The most significant distinction lies in their output signals. A sensor converts a physical quantity being measured into an electrical signal that can be read and processed. A transmitter converts the primary electrical signal from the sensor into a standard electrical signal. such as current signals (4-20mA) or voltage signals (0–10V, 1–5V). Most modern pressure sensors now output standard signals directly. So, pressure sensors and pressure transmitters may be combined into the same device.
Read More about: Pressure Transmitter Output Signal You Should Know
Both a pressure transducer and a pressure transmitter can be referred to as a pressure sensor. However, a pressure sensor cannot be called a pressure transmitter or a pressure transducer. We generally classify pressure transducers and pressure transmitters into the same classification. The main difference is that pressure transmitters have longer transmission distances and more complex structures. Their other basic functions are similar.
This article will primarily introduce the differences between pressure sensors and pressure transmitters.
Different Definition
What is a pressure sensor?
A pressure sensor is a device that detects pressure and converts the pressure signal into a usable electrical signal output. Typically, a pressure sensor refers to a component-level product with a non-standard mV signal output. It serves as the core component of a pressure transmitter. Due to the non-standard nature of the signal, users must perform pressure calibration and use dedicated signal processing circuits when applying the product. Since the sensor signal is weak, an amplifier is often required for long-distance transmission.
What is a pressure transmitter?
A pressure transmitter is a device that measures the pressure of liquids, gases, or steam. Generally, a pressure transmitter primarily consists of three parts: a pressure sensor, a measurement circuit, and a process connection. A Pressure Transmitter converts the physical pressure parameters sensed by the pressure-measuring element sensor into standard electronic signals. The standard electrical signal is supplied to secondary instruments. such as indicating alarms, recorders, and controllers. The secondary instrument then processes, analyzes and records the signal.
Different Working Principle
How Does a Pressure Transmitter Work?
The working principle of a pressure transmitter can be divided into the following steps: The pressure sensor detects the pressure signal and converts it into an electrical signal. The signal processing circuit amplifies, filters, and linearizes the electrical signal. An A/D converter converts the analog signal into a digital signal. The output circuit converts the digital signal into a standardized signal. (e.g., 4-20mA, 0-10V) for long-distance transmission and reception.
How Does a Pressure Sensor Work?
The working principle of a pressure sensor is based on the conversion of physical quantities. When the measured pressure acts upon the sensing element, pressure causes the element to deform. The element deformation induces changes in the physical properties of the conversion element, such as resistance, capacitance, or inductance. These changes are then converted into electrical signal outputs via signal processing circuits. Pressure sensors are typically constructed from specialized materials: metals, crystals or ceramics.
Read More about: 7 Types of Pressure Sensors: Different Types, Working Principles, and Definitions
Applications of Pressure Sensors and Pressure Transmitters
Because pressure sensors are susceptible to electromagnetic interference and have relatively low cost and integration, they are typically used in applications where signal transmission distances are short.
Pressure transmitters, on the other hand, are less susceptible to electromagnetic interference and are therefore typically used in applications where signal transmission distances are longer.
Application Scenario of Pressure Sensors:
Pressure sensors are widely used in industries: hydraulics, pneumatics, automotive, HVAC, aerospace, and laboratory equipment. They can measure the pressure of many media such as liquids, gases, solids, and steam.
Applications Scenario of Pressure Transmitters:
Pressure transmitters are based on pressure sensors but offer broader functionality and more comprehensive performance. They are primarily used in many industrial automation controls. It is typically used for pressure monitoring in manufacturing processes. They measure and regulate pressure within many industrial systems. A pressure transmitter can interface with systems like a PLC for more extensive data processing.
Sino-Inst Featured Pressure Measurement Device
How to Select the Perfect Pressure Measurement Equipment?
Based on our years of pressure measurement experience, we have summarized the key considerations for selecting pressure measurement instruments. By taking the following factors into account, your pressure measurement equipment will ensure long-term stable working.
Operating Environment
Determine the required pressure measurement range. And ensure the selected pressure sensor’s measurement range covers this range. Simultaneously, consider the ambient temperature range and choose a pressure sensor capable of reliable operation under these conditions. Select corresponding high-temperature or cryogenic pressure sensors. Identify the measured medium—liquid, gas, or corrosive substances. Select corrosion-resistant, waterproof pressure sensors to ensure long-term and stable working.
Technical Parameters
Determine the required measurement accuracy based on actual needs. And choose a pressure sensor with the appropriate accuracy class. Select a pressure sensor with a response speed. It is necessary to choose a suitable device for your application scenario. However, different applications may require different response times. Generally, faster response times are preferable, but this must align with your specific usage requirements.
Determine the most suitable signal output. Common signals include current signals, voltage signals and analog signals. The specific signal type depends on your actual data processing regulations.
Structure Types
Pressure sensors can be categorized by operating principle into capacitive, resistive, piezoresistive, and other types. Select the operating principle that best aligns with your application needs.
Additionally, choose the right mounting method based on your measurement vessel. Common mounting methods include threaded connections, flange connections, and insertion types.
Price and Cost-Effectiveness
Choose the most cost-effective pressure sensor based on your budget. Balance performance, quality, and cost-effectiveness comprehensively.
Brand and Quality
Select pressure sensor brands with a solid reputation and reliable quality. Avoid unnecessary complications caused by quality issues. Sino-Inst is a premium supplier highly regarded by customers. You can choose us without doubt.
After-Sales Service and Support
Select manufacturers or suppliers offering robust after-sales support. Ensure timely access to technical assistance and maintenance during product use. Understand the technical support provided by the manufacturer or supplier to guarantee prompt issue resolution when needed. We offer a one-year warranty, supporting returns or replacements for product issues within this period.
Calibration and Validation
Calibrate the sensor before installation and use to ensure measurement accuracy. Most suppliers calibrate sensors prior to shipment. Discuss specific details with your supplier. Regular sensor validation is critical for maintaining long-term stable operation. Selecting sensors with straightforward calibration and validation procedures is also a key consideration.
What is the difference between a pressure transmitter and a pressure switch?
A pressure transmitter converts pressure signals into analog or digital signals for use with amplification circuits. It enables the implementation of processes from pressure detection to control and display.
A pressure switch is a functional switch that automatically connects or disconnects when the pressure reaches a preset value.
Read More: Difference between a Pressure Switch and a Pressure Sensor
What is the main purpose of a transmitter?
A transmitter is a device that converts an input current signal into a standard electrical signal (e.g., 4-20mA, 0-5V). It enables rapid and precise measurement of parameters such as temperature and pressure. These measurements are isolated and converted into standard analog signal outputs.
How to connect a transmitter to a PLC?
1. If pressure display is unnecessary, connect a digital output transmitter (amplifier) to the PLC. Communication interfaces can be RS232 or RS485.
2. If pressure values need to be displayed, use a display controller with a communication interface connected to the PLC. The communication interface can be RS-232, RS-485, or an Ethernet port.
Connecting to the PLC via digital signals provides higher measurement accuracy. Although the sampling rate of serial ports is limited, the cost is relatively low compared to analog signal connections. This is particularly advantageous when a single device uses multiple pressure sensors, as one serial port can connect to multiple pressure sensors.
Most suppliers provide corresponding wiring diagrams. If you require specific connection methods, please contact your supplier.
In summary, the conversion from a pressure sensor to a transmitter involves transforming raw signals into standardized outputs. Pressure sensors and transmitters need not be strictly distinguished; simply select different pressure sensors based on your specific operating conditions.
If you require pressure measurement but face selection problems, contact us immediately. Our professional engineers will provide the most cost-effective measurement solutions. With years of expertise in pressure measurement, Sino-Inst boasts numerous successful pressure measurement case studies.
