Pressure Sensor Glossary
Understanding pressure sensing terminology is essential when selecting the right sensor for industrial, HVAC/R, hydraulic, refrigeration, automotive, and process control applications. This glossary provides clear definitions of commonly used pressure measurement terms and sensor technologies.
A
Absolute Pressure
Pressure measured relative to a perfect vacuum (0 bar absolute). Absolute pressure sensors contain an internal vacuum reference chamber and are commonly used in weather monitoring, vacuum systems, and engine management applications.
Accuracy
The maximum deviation between the sensor output and the ideal pressure value. Accuracy is typically expressed as a percentage of Full Scale (%FS) and may include linearity, hysteresis, and repeatability errors.
Ambient Temperature
The temperature of the environment surrounding the sensor housing. Ambient temperature can influence sensor performance and compensation requirements.
Analog Output
A continuous electrical output signal proportional to pressure, commonly available as:
* 0.5–4.5 VDC
* 0–5 VDC
* 1–5 VDC
* 4–20 mA
B
Bar
A metric unit of pressure.
* 1 bar = 100 kPa
* 1 bar ≈ 14.5 psi
Burst Pressure
The maximum pressure a sensor can withstand before mechanical failure occurs. Exceeding burst pressure may permanently damage the sensing element.
Bridge Circuit
An electrical circuit, typically a Wheatstone Bridge, used in piezoresistive MEMS pressure sensors to convert diaphragm strain into a measurable electrical signal.
C
Calibration
The process of comparing and adjusting a sensor's output against a known pressure standard to ensure measurement accuracy.
Compensation
Electronic correction techniques used to reduce errors caused by temperature changes, non-linearity, and manufacturing variations.
Common Mode Pressure
The pressure applied equally to both ports of a differential pressure sensor.
D
Deadband
The pressure difference between the actuation point and reset point of a pressure switch.
Differential Pressure
The pressure difference between two separate pressure ports.
Differential pressure sensors are commonly used in:
* HVAC air flow monitoring
* Filter condition monitoring
* Cleanroom pressure control
* Refrigeration systems
Digital Output
A pressure signal transmitted using digital communication protocols such as:
* I²C
* SPI
* CANbus
* LIN
* RS485
F
Full Scale (FS)
The complete calibrated pressure measurement range of a sensor.
Example:
0–10 bar sensor = 10 bar Full Scale
Full Scale Output (FSO)
The electrical output produced when the sensor is exposed to its maximum rated pressure.
G
Gauge Pressure
Pressure measured relative to atmospheric pressure.
A gauge pressure sensor reads:
* 0 bar when exposed to atmosphere
* Positive pressure above atmosphere
* Negative pressure (vacuum) below atmosphere
Gauge pressure measurement is the most common pressure sensing method used in industrial equipment.
H
Hermetic Seal
A gas-tight sealing structure that prevents moisture, contaminants, or media intrusion into the sensing element and electronics.
Hermetically sealed sensors are widely used in:
* Refrigeration systems
* Hydrogen applications
* Industrial hydraulics
* Automotive systems
Hysteresis
The difference in output when a pressure point is approached from increasing pressure versus decreasing pressure.
Lower hysteresis results in higher measurement accuracy.
L
Linearity
The degree to which sensor output follows a straight-line relationship with applied pressure.
Better linearity improves overall measurement performance.
Long-Term Stability
The ability of a pressure sensor to maintain its calibration and performance characteristics over extended periods of operation.
M
MEMS Pressure Sensor
A pressure sensing device manufactured using Micro-Electro-Mechanical Systems (MEMS) technology.
Advantages include:
* Miniaturization
* High reliability
* Low power consumption
* High-volume production capability
* Excellent repeatability
Media Compatibility
The ability of wetted materials to withstand exposure to specific liquids or gases without degradation.
Common wetted materials include:
* 316L Stainless Steel
* Silicon
* Ceramic
* Hastelloy
* Titanium
O
Overpressure
The maximum pressure that can be applied without causing permanent calibration shift or damage.
Overpressure rating is typically lower than burst pressure.
Output Signal
The electrical signal generated by a pressure sensor corresponding to measured pressure.
Common outputs include:
* mV/V
* Voltage
* Current
* Digital interfaces
P
Pressure Range
The minimum and maximum pressures that a sensor is designed to measure accurately.
Pressure Transducer
A device that converts pressure into an electrical output signal.
Pressure transducers are commonly used in OEM equipment and industrial automation systems.
Pressure Transmitter
A pressure sensor with integrated signal conditioning electronics that provides standardized outputs such as:
* 4–20 mA
* 0–10 V
* Modbus
* CANopen
Proof Pressure
The maximum pressure that may be applied without causing permanent performance degradation.
R
Repeatability
The ability of a sensor to produce the same output when the same pressure is applied repeatedly under identical conditions.
Response Time
The time required for a sensor output to reach a specified percentage (typically 90%) of its final value after a pressure change.
l
S
Sensitivity
The amount of output signal change produced by a given change in pressure.
Silicon Piezoresistive Technology
A sensing technology that utilizes the piezoresistive effect of silicon. Mechanical stress on the diaphragm changes electrical resistance, producing a pressure-dependent signal.
Span
The difference between the upper and lower pressure limits of the measurement range.
Example:
0–100 psi = 100 psi span
Static Accuracy
The total measurement error under stable environmental conditions.
T
Temperature Compensation
Electronic correction applied to minimize output drift caused by temperature variations.
Thermal Drift
Changes in sensor output caused by temperature fluctuations rather than actual pressure changes.
Total Error Band (TEB)
A comprehensive specification that combines:
* Accuracy
* Linearity
* Hysteresis
* Repeatability
* Thermal effects
TEB provides a realistic indication of sensor performance across the operating temperature range.
V
Vacuum Pressure
Pressure below atmospheric pressure.
Vacuum measurement is commonly used in:
* Medical equipment
* Laboratory systems
* Refrigeration systems
* Industrial process control
W
Wetted Materials
Materials that come into direct contact with the measured fluid or gas.
Proper wetted material selection is critical for:
* Corrosion resistance
* Chemical compatibility
* Long-term reliability
* Safety compliance
Related Technologies
* MEMS Pressure Sensors
* Pressure Transmitters
* Pressure Switches
* Differential Pressure Sensors
* Refrigeration Pressure Sensors
* HVAC/R Pressure Sensors
* Hydraulic Pressure Sensors
* Industrial Pressure Measurement
* Temperature & Pressure Sensors (P+T Sensors)
* Digital Pressure Sensors
This glossary is intended to help engineers, system designers, OEM manufacturers, and maintenance professionals better understand pressure sensing technologies and measurement principles used across industrial and commercial applications.