# Relative humidity sensor

Canonical URL: https://eloragrid.ai/symbols/relative-humidity-sensor
Publisher: Elora Grid
Updated: 2026-10-27
Lookup label: RH
Drawing use: Schematic
Reference families: Manufacturer

A relative humidity sensor measures moisture in air relative to the saturation condition at the relevant temperature.

## In plain English

### What does Relative humidity sensor mean?

A relative humidity sensor measures moisture in air relative to the saturation condition at the relevant temperature.

### A simple example

A switchroom monitor can report humidity alongside temperature when assessing its environment.

### What the drawings help you do

Identify the air location being monitored and show temperature information where the selected interpretation needs it. Relative humidity compares water vapour with saturation at the relevant temperature. This is why the same moisture content can produce a different relative-humidity value as temperature changes.

### Before using this reference

- Identify the sensor’s air location and exposure.
- Distinguish humidity and temperature outputs.
- Reference the selected sensor’s mounting and response requirements.

### Is relative humidity the same as the mass of water in the air?

No. Relative humidity is a temperature-dependent comparison with saturation. Absolute moisture quantities describe something different, so label the reported quantity and units clearly.

### Terms

- Relative humidity: Moisture in air compared with saturation at the relevant temperature.
- Saturation: The condition used as the reference for that temperature-dependent comparison.

Concept diagram: Air moisture and temperature → Humidity sensing element → Relative-humidity reading
Original functional explanation. Arrows show information or energy roles; two-headed arrows identify two-way interfaces. This is not a pinout, certified standards graphic or complete circuit.

- [Humidity sensing principles](https://www.ti.com/lit/an/snaa318/snaa318.pdf)


## What it represents

A relative humidity sensor measures moisture in air relative to the saturation condition at the relevant temperature.
A switchroom monitor can report humidity alongside temperature when assessing its environment.
Identify the air location being monitored and show temperature information where the selected interpretation needs it. Relative humidity compares water vapour with saturation at the relevant temperature. This is why the same moisture content can produce a different relative-humidity value as temperature changes. This is original functional artwork, not a certified standard graphic or device pinout.

## How to read it

- Identify the sensor’s air location and exposure.
- Distinguish humidity and temperature outputs.
- Reference the selected sensor’s mounting and response requirements.
- Relative humidity and absolute water content are different quantities.

## Information to show or reference

- Identify the sensor’s air location and exposure.
- Distinguish humidity and temperature outputs.
- Reference the selected sensor’s mounting and response requirements.

## Important distinction

Relative humidity and absolute water content are different quantities.

## Facts

- Representation type: Original functional block; not a certified IEC or IEEE graphic
- Concept input: Air moisture and temperature
- Concept output: Relative-humidity reading

## Public references

- [Humidity sensing principles](https://www.ti.com/lit/an/snaa318/snaa318.pdf) — Texas Instruments. Humidity sensing principles: public technical context for the named function. Product and compliance details remain with the publisher.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.