Skip to main content

Humidity Sensor Working Principle

 Impedance type Humidity Sensor: Accurate, fast and reliable ceramic moisture sensor for the measurement of absolute humidity in process air and gases


The principle of operation is quite simple. Operation of the sensor depends upon the adsorption of water vapour into a porous non-conducting “sandwich” between two conductive layers built on top of a base ceramic substrate. The active sensor layer is very thin – less than one micron (a millionth of a metre) and the porous top conductor that allows transmission of water vapour into the sensor is less than 0.1 micron thick. Therefore the sensor responds very rapidly to changes in applied moisture, both when being dried (on process start-up) and when called into action if there is moisture ingress into a process.


The resistance or impedance of the sensor ceramic layers changes with the water vapour applied to it. Finally converting the change in impedance will give us the humidity value.


Comments

  1. Thanks for this wonderful and detailed information about the working principle of the humidity sensor. As I read the whole article and will say one thing the author describes the working principle of the humidity sensorin a very simple way that anyone can understand very quickly. It really helps those who want to learn about humidity sensors.

    ReplyDelete

Post a Comment

Popular posts from this blog

Ferrules and Cross Ferruling

 Ferrules are identification labels provided for every wire terminations in an instrument, equipment, or electrical/instrumentation control panels. These tube-shaped sleeves can be inserted easily on each individual wire in a multi-core cable. In earlier days fixed digits/letters are used as ferrules, but now Instrumentation engineers/technicians prints out desired ferrules by using a ferrule printing machine. Typical Ferrule The numbers/ letters on the ferrules will be given as per the approved electrical hook up or loop diagrams. This helps technicians to easily identify a particular loop/wiring from a series of terminal blocks and to troubleshoot the desired terminal connection. Separate numbers on the ferrules distinguish the positive and negative polarities of wires, thus ensure the polarity protection of the instrument. Cross Ferruling  As a wire is connected on its both ends, it is quite useful to use a cross reference method for wire identification. Unlike normal ferru...

What is a Torbar? – Averaging Pitot Tubes

 The Torbar is employed for flow measurement of liquids, gases, or steam in circular, square, or rectangular section ducts for large flow rates. The Torbar is an insertion type multi-port self-averaging primary sensor for flow measurement. Torbar TORBAR is a set of Pitot tubes mounted on a bar across the pipeline with no moving parts. An averaging Pitot tube is a technology, while TORBAR is a manufacturing brand name. There are several brands available in the market with VERABAR, ANNUBAR, etc. Averaging Pitot Tube Principle Purpose Averaging Pitot tube can be employed when the average velocity of the flow profile, rather than the velocity in a specific point in the cross-section is desired. Averaging Pitot Tubes Principle It measures the differential pressure between the static pressure tap and the tap of full pressure of a stream. Thus such magnitude of differential pressure is directly proportional to the square of the flow rate. Working The TORBAR is designed in such a way that ...

The Method and Process of Siemens PLC Hardware Configuration

 The hardware configuration of Siemens PLC can usually adopt the following methods and processes: Determine control tasks and system requirements: Before hardware configuration, it is necessary to clarify the tasks and requirements of the control system, including the requirements for input and output points, control accuracy, speed, and safety. Select the PLC model and module: According to the control task and requirements, select the appropriate PLC model and module, including CPU, I/O module, communication module, power supply module, etc. Assemble the cabinet and install the modules: According to the selected PLC model and module, assemble the cabinet and install the modules, pay attention to the installation sequence, cable wiring, wiring method, etc. Connect the input and output devices: connect the input and output devices with the input and output modules of the PLC, you need to pay attention to the correctness, stability and safety of the wiring. Perform software configura...