This section provides an overview for hygrometers as well as their applications and principles. Also, please take a look at the list of 19 hygrometer manufacturers and their company rankings.
Table of Contents
A hygrometer is a device that measures and displays the humidity in the air. There are several indicators of humidity, but the one we use every day is relative humidity (%RH). The relative humidity is the ratio of the amount of water vapor in the air being measured to the maximum amount of water vapor the air can contain at that temperature. Other parameters besides relative humidity include mixing ratio (kg/kg), absolute humidity (g/m^3), water vapor pressure (Pa), dew point temperature (°C), and mole fraction (mol/mol ).
There are two types of hygrometers: analog and digital.
Analog types include dry and wet hygrometers, hair hygrometers, and bimetallic hygrometers; the oldest ones have been used since around 1500. Basically, they do not use electricity. They are prone to errors and require maintenance and measurement conditions.
Digital electronic hygrometers are sensors that use semiconductors and are often combined with a temperature sensor to make a temperature/hygrometer. They are used for industrial applications because of their small size and easy data recording.
Hygrometers have long been used for public weather observation. They are also used in weather forecasts, which are communicated to us along with the temperature.
Hair hygrometers are used in museums and art galleries because they do not require electricity. As industrial hygrometers, they are used in places where humidity is sensitive, such as in the cultivation of plastic greenhouses and mushrooms in agriculture and in medical and pharmaceutical plants.
Recently, temperature and humidity gauges are increasingly being used to prevent heat stroke. They are deployed in large gymnasiums, classrooms, nursing homes, and other indoor places where people are engaged in activities. They are also installed in air conditioners and humidifiers and are responsible for the automatic control of the equipment.
Various principles are used to measure humidity. First of all, the principles are largely divided into analog and digital types. The following is a description of the most common types of hygrometers.
Analog hygrometers are often used in hygrometers used for daily necessities.
Wet and Dry Spherical Hygrometer
The wet and dry spherical hygrometer consists of two glass thermometers side by side, one of which is wrapped with gauze containing water. The gauze absorbs the moisture in the container and evaporates at the wrapped thermometer. As the water evaporates, the heat of vaporization is lost, so the thermometer with the gauze wrapped around it displays a lower temperature (wet-bulb temperature). From this temperature difference, humidity is calculated. Some products have a wet-bulb temperature conversion chart between the two thermometers to read humidity from the difference between the wet-bulb temperature and the thermometer without the gauze (dry-bulb temperature); if the two thermometers have the same number, the wet cloth has not dried, and no vaporization heat has occurred, meaning 100% humidity. The humidity is 100%.
Hair Hygrometer
The hair hygrometer uses the elasticity of nylon threads and human hair to move the needle. The needle is enlarged using the principle of leverage, and the movement is recorded on a roll of paper. Since measurements are made without the use of electricity, there is no risk of fire, and these instruments can be found in museums and other places.
Bimetal Hygrometer
The bimetallic hygrometer uses a metal spring as the base, to which is laminated with a dry humidity agent with a different shrinkage rate that easily absorbs moisture, and the shape of the spring changes according to humidity. It is used in wall-mounted pointer-type hygrometers.
Digital hygrometers are widely used in industrial applications.
Electric Resistance Type
The electrical resistance type uses a humidity element whose electrical resistance changes according to relative humidity. 20%RH or lower humidity is impossible to measure due to a large error, and the element deteriorates due to high temperature.
Capacitance Type
The capacitance type uses the change in electrical capacitance stored in a capacitor. The amount of moisture adsorbed or released by the polymer film inside the capacitor is proportional to the relative humidity in the air. Unlike the electrical resistance type, it can measure from 0% relative humidity.
Dew-point Hygrometer (optical)
The dew point is measured by shining the air to be measured onto a chilled mirror and detecting the fogging of the mirror from the reflection of light. The dew point temperature is the temperature at which the mirror begins to fog up. In addition, relative humidity can be separately calculated in conjunction with the air temperature. This is currently the most accurate method of measuring humidity.
Although we have introduced several humidity measurement methods, they have different error margins. While it is desirable for the measurement to be correct, it is also important to be easy to measure. For daily life, ease is more important than accuracy, and for industrial use, it is necessary to select a measurement method with an error range that can meet the objective. When selecting an instrument, be sure to check the measurable range and error range thoroughly.
*Including some distributors, etc.
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Micro Quality Calibration Inc MQC) was founded in 1978 as a technology-oriented calibration, repair, testing, and first article inspection facility for precision measurement test equipment. MCQ follows in strict compliance of ISO-9000 (series 1, 2, 3, and 4) specifications. MCQ offers services in calibration, inspection testing, repair, database management, and analytics. Calibration services are often provided for automotive, electrical components, aerospace, and secure communications, for which MCQ is ISO 17025 accredited.
Dynalab Corp was founded in Rochester, New York in 1957. Together with its wholesale division, Dynalon Labware, Dynalab produces and distributes standard and custom-made scientific equipment and laboratory supplies across North America. Science equipment and sampling apparatus offerings include hygrometers, mailing point devices, rollers, water stills, powders, seals, various samplers, and drills. Some of Dynalab’s laboratory supplies include Azlon plastics, burn-up boxes, desiccators, hydrometers, pipettes, shields, stopcocks, tote boxes, tubing, and watch glasses.
Sterling Sterlco was founded in 1916 and distributes under M&M Control Service, Inc. is a specialist in industrial control units. Industrial control units are in two basic varieties: steam control family and temperature control units. Steam Control units include steam traps, Y strainers, temperature control valves, hand radiator valves, boiler feed pumps, condensate pumps, and centrifugal pumps. Temperature control units include portable chillers, central chillers, and water and oil temperature control units. Additionally, Sterling also manufactures pump tanks.
Broner Glove and Safety has served customers since 1933 and is based in Auburn Hills, Michigan. Broner is a safety service provider as well as distributor of safety equipment. Broner’s safety equipment offerings include first aid emergency response equipment, ergonomic assisting tools, eye protection, fall protection, hearing protection, instrumentation, plant and site safety equipment, welding-use protection, respiratory protection, protective apparel and more. Safety services include glove testing, plant surveys, safety glass programs, respiratory fit testing, and transaction analysis among others.
MOD-TRONIC Instruments Limited was established in 1972 in Brampton, Ontario, Canada. MTis a distributor of industrial sensors, transducers, heaters, controls, and instrumentation, primarily made in the USA as well as Japan, Switzerland, and Germany. MT’s customers are primarily in the aerospace, building automation, manufacturing, medical, military, oil and gas, and water treatment industries but also serves individuals. MT offers an above industry standard 5-year warranty and technical support on every product sold.
Ranking as of March 2023 in United States of America
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | PCE Instruments | 40% |
2 | Abbeon Cal Inc. | 20% |
3 | Extech Instruments Corp. | 20% |
4 | Broner Glove & Safety Company | 20% |
Ranking as of March 2023 Globally
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | PCE Instruments | 40% |
2 | Abbeon Cal Inc. | 20% |
3 | Extech Instruments Corp. | 20% |
4 | Broner Glove & Safety Company | 20% |
Derivation Method
The ranking is calculated based on the click share within the hygrometer page as of March 2023. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History
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