# Pressure Sensor (IL)

Measure pressure differences, absolute pressure, or gauge pressure

• Library:
• Simscape / Foundation Library / Isothermal Liquid / Sensors

## Description

The Pressure Sensor (IL) block represents an ideal sensor that measures pressure in an isothermal liquid network. There is no mass flow through the sensor.

The Pressure Measurements parameter controls the measurement type and sensor configuration:

• `Pressure difference` — The physical signal port P reports the pressure difference across the sensor:

`$P={p}_{A}-{p}_{B},$`

where pA and pB are pressures at the sensor ports. The measurement is positive when the value at port A is greater than the value at port B.

• `Absolute pressure` — The physical signal port Pa reports the absolute pressure at port A:

`$Pa={p}_{A},$`

where pA is pressure at port A, measured with respect to absolute zero. In this configuration, the sensor has only one isothermal liquid port.

• `Gauge pressure` — The physical signal port Pg reports the gauge pressure at port A:

`$Pg={p}_{A}-{p}_{atm},$`

where pA is pressure at port A, measured with respect to absolute zero, and patm is the atmospheric pressure specified by the Isothermal Liquid Properties (IL) block connected to the circuit. In this configuration, the sensor has only one isothermal liquid port.

The block icon changes depending on the value of the Pressure Measurements parameter.

Pressure MeasurementsBlock Icon
`Pressure difference`

`Absolute pressure`

`Gauge pressure`

## Ports

### Output

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Physical signal output port for the pressure difference measurement.

#### Dependencies

This port is visible if you set the Pressure Measurements parameter to `Pressure difference`.

Physical signal output port for the absolute pressure measurement.

#### Dependencies

This port is visible if you set the Pressure Measurements parameter to `Absolute pressure`.

Physical signal output port for the gauge pressure measurement.

#### Dependencies

This port is visible if you set the Pressure Measurements parameter to `Gauge pressure`.

### Conserving

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Isothermal liquid conserving port.

Isothermal liquid conserving port.

#### Dependencies

This port is visible if you set the Pressure Measurements parameter to `Pressure difference`.

## Parameters

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Select the type of measurements:

• `Pressure difference` — The sensors measures the pressure difference across the sensor. Selecting this option exposes the physical signal output port P and the second isothermal liquid port B. The measurement is positive when the value at port A is greater than the value at port B.

• `Absolute pressure` — The sensors measures the absolute pressure at port A. Selecting this option exposes the physical signal output port Pa.

• `Gauge pressure` — The sensors measures the gauge pressure at port A. Selecting this option exposes the physical signal output port Pg.

## Version History

Introduced in R2020a