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Brownell Glossary
Whether you’re an industry professional or new to the field, we know technical terminology can be complex. This page provides clear definitions of key terms and abbreviations related to our products and services, helping you navigate industry-specific language with ease. Whether you're looking for information on moisture control and desiccants or RF screening and EMI Shielding, our glossary is here to assist you. If you have any further questions or need clarification, feel free to contact our team.
A
- Absolute Humidity (AH)
The total mass of water vapor present in a given volume of air, typically expressed in grams per cubic meter, and is influenced by the air's temperature and pressure. - Absolute Pressure (PSIA)
Pressure measured relative to a perfect vacuum, expressed in pounds per square inch absolute. - Absorption v Absorbent
Absorption refers to the process where one substance is taken up internally by another, such as a liquid being absorbed into a solid. An absorbent is a material or substance that performs the act of absorption. - Adiabatic Saturation
The process of saturating air with moisture without the exchange of heat with its surroundings, typically achieved by passing air over a water surface. - Air Flow Rate (SLPM)
The volume of air flowing through a system per unit of time, measured in Standard Litres per Minute. - Anhydrous
Describing a substance which contains no water. - Atmospheric Pressure
The pressure exerted by the weight of the atmosphere at a given point, typically measured in Pascals (Pa) or atmospheres (atm).
B
- Barometric Pressure
The atmospheric pressure as measured by a barometer, typically expressed in millibars (mbar) or inches of mercury (inHg).
C
- Cathodic Protection
A method used to prevent corrosion of metal surfaces by making them the cathodic side of an electrochemical cell. - Computational Fluid Dynamics (CFD)
A field of fluid mechanics that uses numerical analysis and algorithms to solve and analyse fluid flow. - Coordinate-measuring machine (CMM)
A device that measures the physical geometries of an object in a very precise manner, using a calibrated probe that touches the object's surface.
D
- Desiccant
The process of removing moisture from a substance or environment to preserve materials or prevent damage caused by humidity. - Desiccation
A container or other apparatus holding a drying agent such as Silca Gel Desiccant, used for removing moisture from equipment and environments to protect them from water vapour that is present in the surrounding air. - Desiccator
The process of releasing a substance, such as vapour molecules, from a surface into a fluid or vacuum. - TBC
The process of releasing a substance, such as vapour molecules, from a surface into a fluid or vacuum. - Dew Formation
The condensation of water vapor into liquid droplets on surfaces when the temperature drops below the dew point. - Dew Point
The atmospheric temperature (varying according to pressure and humidity) at which air becomes saturated with moisture and water vapor begins to condense into liquid. - Dew Point Temperature
The temperature at which the dew point is reached. - Dielectric loss
The loss of energy in an insulating material, occurring as heat when a varying electric field causes the material to absorb energy. - Dry Bulb Temperature
The ambient air temperature measured by a thermometer that is not affected by moisture.
E
- Electrostatic Discharge (ESD)
A sudden and momentary flow of electric current between two differently-charged objects when brought close together or when the dielectric between them breaks down. - EMC Shielding
Electromagnetic Compatibility (EMC) shielding is used to protect devices from electromagnetic interference (EMI) by absorbing or blocking electromagnetic fields.
F
- TBC
TBC - TBC
TBC
G
- Gauge Pressure (PSIG)
Pressure measured relative to the atmospheric pressure, expressed in pounds per square inch gauge. - Gasket
A sealing material placed between two surfaces to prevent leakage of fluids or gases.
H
- Hermetic Sealing
The process of creating an airtight seal between two or more components, preventing gases, liquids, and solids from passing through. - Humectants
Humectants are hygroscopic substances that retain moisture by attracting water molecules from the environment. - Hydrophobic Membrane
A piece of thin material where its surface repels water or does not mix with it, but allow gas molecules to flow freely. - Hydrophobicity
The property of a material that repels water, preventing it from wetting the surface. Hydrophobic materials are commonly used in coatings, membranes, or other applications where water resistance is essential. - Hydrostatic Pressure
The pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. It therefore increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above. - Hygroscopic
A material's ability to absorb moisture from its surroundings, such as water vapor in the air. Hygroscopic materials such as desiccants are often used in applications where avoiding moisture damage is crucial.
I
- Inlet Filter
A filter placed at the entrance (inlet) of a system or machine with the purpose of cleaning incoming air, gas, or liquid before it enters the machinery, thereby protecting the internal components. - Ingress Protection (IP) Rating
A standard indicating the level of protection against dust and water intrusion in equipment and enclosures, as defined by the International Electrotechnical Commission (IEC).
J
- TBC
TBC - TBC
TBC
K
- TBC
TBC - TBC
TBC
L
- Leak Rate
The rate at which gases such as helium or nitrogen escape through a system or container, used to evaluate sealing integrity.
M
- Moisture Adsorbing Polymer
A type of polymer, which is usually chemically blended with desiccant, moulded to block or sheet form, to absorb moisture from the air or surroundings. - Moisture Barrier
A layer or material designed to block moisture from penetrating into sensitive areas or materials. - Moisture Ingress
The unwanted entry of moisture into enclosures or systems, which can cause damage or malfunction. - Moisture Vapour Transmission Rate (MVTR)
The rate at which water vapor passes through a material or substance, usually measured in grams per square meter per day (g/m2/24hr).
N
- TBC
TBC - TBC
TBC
O
- Outgassing
The release of trapped gas or vapor from a solid or liquid material, often occurring in a vacuum or high-temperature environment. - Overpressure
A condition where the pressure inside a vessel or system exceeds the design or safe limit.
P
- Pressure Differential (PSID)
The difference in pressure between two points in a system, measured in pounds per square inch differential.
Q
- TBC
TBC - TBC
TBC
R
- Rapid Decompression
An event in which the decompression happens in a matter of seconds. It may cause containers of weak structure to explode or implode if an appropriate pressure relief device is not installed. - REACH Compliance
The process of following the European Union's (EU) Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation. REACH aims to protect human health and the environment from the risks of chemicals. - Relative Humidity (RH)
The amount of water vapour present in air expressed as a percentage of the amount needed for saturation at the same temperature. - RoHS Compliance
A set of regulations put in place by the European Union to protect human health and the environment from the harmful effects of certain hazardous substances.
S
- TBC
TBC - TBC
TBC
T
- Thermal Expansion/Contraction
The tendency of matter to change in length, area, or volume, changing its size and density, in response to a change in temperature. - Thermal Management
Techniques used to control the temperature of devices and systems to ensure optimal performance and prevent overheating.
V
- Vacuum Pressure (PSIV)
Pressure below atmospheric pressure, measured in pounds per square inch vacuum. - Vapor Pressure Deficit (VPD)
The difference between the amount of moisture in the air and how much moisture the air can hold. A measure of dryness, or aridity, near the Earth's surface. - Vapour Pressure
The pressure exerted by a vapour in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. - Volatile Organic Compounds (VOCs)
Organic chemicals - commonly found in paints, solvents, adhesives, and cleaning products - that easily evaporate at room temperature, often contributing to air pollution and health hazards.
W
- Wet Bulb Temperature
The lowest temperature that air can reach through the process of evaporative cooling, measured by a thermometer covered in a wet cloth.
X
- TBC
TBC - TBC
TBC
Y
- TBC
TBC - TBC
TBC
Z
- TBC
TBC - TBC
TBC
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