Glossary

Digital-to-analog.

The consigner gives instructions to his bank stating that the documents are linked to a bill of exchange and the goods will be delivered to the acceptor if he accepts the bill of exchange.

Instructions given by the consigner to his bank in which he states that the documents are linked to a bill of exchange, and these documents must be given to the acceptor as soon as he makes the payment of the bill of exchange.

Digital-to-analog converter.

A device for introducing a variable pressure drop in a system used for regulating the volumetric flow of a gas, such as air.

A device used to control the volume of air passing through an air outlet, air inlet or duct.

A blade or set of blades that can be moved within or slid into a duct in order to control fluid flow.

The fan performance is controlled by means of a damper, either on the inlet or on the outlet, creating a variable additional system resistance.

The dissipation of energy with time or distance. The term is generally applied to the attenuation of sound in a structure owing to the internal sound dissipative properties of the structure or to the addition of sound dissipative materials.

The power supply available from batteries, generators (not alternators), or a rectified source used for special purpose applications.

A current with a constant polarity.

Removal of air and gases from boiler feed water prior to its introduction to a boiler.

Money borrowed from lenders for a variety of corporate or personal purposes. The borrower pays interest for the use of the money and is obligated to repay the principal amount on a set date.

A measure of how much debt your business has in relation to the amount of equity invested in it. A high level of debt to equity can be of concern. To support your company, you can raise money either by borrowing it (incurring a debt) or by selling ownership in the company (equity). To calculate, divide total Liabilities by Equity.

Time delay between the injection of tracer gas and the rise in concentration of tracer gas in the sampled air.

A unit of measure of the intensity of sound. 

A decibel is the common unit of measure of sound.

A decibel is one tenth of a bel. An increase of 1 bel approximately double the loudness of a sound. For example: breathing, 5 dB; office activity, 50 dB; jet aircraft during takeoff at a distance of 300 feet, 130 dB standard weightings used for various reasons. In this case we shall only be concerned with "A-weighting." 

Cargo which travels outside and not in the holds of the vessel.

A financial situation for an individual, company or government where expenses exceed income.

Removal of gases from samples of steam taken for purity test.
Removal of CO2 from water as in the ion exchange method of softening.

The condensation of water vapour from air by cooling below the dewpoint or removal of water vapour from air by chemical or physical methods.

(1) An Air cooler or washer used for lowering the moisture content of the air passing through it.
(2) An absorption or adsorption device for removing moisture from air.

The exporter fulfils its obligations by delivering the goods to the borders of destination country but before the borders line i.e. without undertaking the Customs formalities. This term usually concerns the goods transported by rail or by the road but can be also used with other means of transport.

The exporter promises to safely transport the goods until the border, which is located before the Customs of the importing country. This is a current practice when goods are dispatched by road or rail.

The exporter is responsible for delivering the goods, for the risks, damages & losses and the payment of Customs duties.

A term which indicates that the exporter should deliver the goods and pay the corresponding taxes. This term can be used without taking account of the real used transports means. If the parties wish to exclude some charges related to the exporter obligations (such as the tax on the added-value or other similar taxes) , they should explicitly state it by adding a special mention for this purpose (such as "excluding VAT and/or taxes").

Document providing the proof of the transfer of responsibility for the goods.

An air pollution control device to remove dispersed water droplets (mist) from gaseous emissions.

The mass of a given substance per unit volume, often expressed as pounds/ft3 or grams/cm3.

A factor applied to correct or convert dry air density of any temperature to velocity pressure.

The ratio of actual flow to ideal flow.

A charge against a fixed asset that writes off the cost of that asset over its useful life. The depreciation amount is entered as an expense in your income statement and is a non-cash expense.

A method of testing for air leakage of a building or component by installing a powerful fan across the envelope and creating a static pressure deficit within the building. The flow rate through the fan and across the envelope are measured and air leakage assessed.

Any absorbent or adsorbent, liquid or solid, that will remove water or water vapour from a material. In a refrigeration circuit, the desiccant should be insoluble in the refrigerant.

The pressure used in the design of a boiler for the purpose of calculating the minimum permissible thickness or physical characteristics of the different parts of the boiler.

The dew point is the temperature to which the air must be cooled, at constant barometric pressure, for water vapor to condense into water. The condensed water is called dew. The dew point is a saturation point.

The difference in static pressure between two locations.

A circular, square, or rectangular air distribution outlet, generally located in the ceiling and comprised of deflecting members discharging supply air in various directions and planes, and arranged to promote mixing of primary air with secondary room air.

Molecular diffusion : Transport of particles or molecules by bombardment with the molecules of the ambient air.

The scattering or random reflection of a sound wave from a surface. The directions of reflected sound are changed so that listeners may have sensation of sound coming from all directions at equal levels.

A measure of the tendency of one gas or vapour to disperse into or mix with another gas or vapour. This rate depends on the density of the vapour or gas as compared with that of air, which is given a value of 1.

The process of increasing the proportion of solvent or diluent (liquid) to solute or particulate matter (solid).

Two groups of chlorinated organic compounds of potential health concern that may be formed at very low levels during combustion.

The power supply available from batteries, generators (not alternators), or a rectified source used for special purpose applications.

A current with a constant polarity.

The water released from some APCDs after processing in a wastewater treatment facility.

Air pressure produced at a particular point in the system under specific conditions.

The total temperature at the discharge connection of the compressor.

The temperature at the discharge flange of the fan.

An agent that frees from infection by killing the vegetative cells of microorganisms.

Document used for export which mentions the quantity and the type of exported goods.

The final disposition of wastes (e.g., landfilling) after recovery and treatment in management hierarchy.

Water produced by vaporization and condensation with a resulting higher purity.

Receipt issued by a maritme transport company or an agent which mentions the time when the goods were delivered on the docks or in the warehouses before their shipping.

Commercial letter of credit issued by a bank on behalf of the beneficiary, generally the vendor of the goods, and on surrender of handing-over of documents specified in the credit letter.

Arrangement by virtue of which a bank acts at the request and on the instructions of a customer or for its own account in order to: - make a payment to a third party or to itself, or to accept and pay bank drafts drawn by the beneficiary, - authorise another bank to carry out the said payment or to accept and pay the said bank drafts. Documentary credit can be revocable or irrevocable.

Documents usually joined to foreign bills of exchange. It could be maritime bills of lading, insurance certificates, commercial invoices and when it's specified the certificates of origin and consular invoices.

Potable hot water as distinguished from hot water used for house heating.

Amount of time a piece of equipment is not operational.

Bill of exchange which is a written payment order from one party (the drawer) to another (the drawee) to pay a stated sum to a third party (the payee) either immediately (in case of a sight draft) or on or before a specified date (in case of a time draft). When presented with shipping and/or title documents, it is called a documentary draft; without them, a clean draft. Also called draft bill of exchange.

Instrument of payment frequently used for business matters. It is a written and unconditional bond or order signed by the exporter obliging the importer to pay a certain amount od money on request or at a precise date. A draft at sight for example requires an immediate payment whereas a usance bill requires the payment within a certain time (from 30 to 180 days).

The difference in static pressure between two points in a system.

A device for measuring draft, usually in inches of water.

An instrument for measuring wind speed by exposing a simple body to the airstream and measuring the drag force on it.

A pipe through which liquid is carried away.

(1) Excessive air movement in an occupied enclosure causing discomfort.
(2) A difference in pressure between a furnace and the atmosphere that causes air for combustion to flow into the furnace and/or the products of combustion to leave the furnace.

Air without water vapour.

Air with which no water vapour is mixed. This term is used comparatively, since in nature there is always some water vapour included in air, and such water vapour, being a gas, is dry.

The temperature registered by an ordinary thermometer. The dry bulb temperature represents the measure of sensible heat, or the intensity of heat.

The temperature indicated by a dry temperature sensing element (such as the bulb of a mercury-in-glass thermometer) shielded from the effects of radiation.

The temperature of a gas or mixture of gases indicated by an accurate thermometer after correction for radiation.

Gas containing no water vapour.

Steam containing no moisture. Commercially dry steam containing not more than one half of one percent moisture.

(1) An enclosure of any cross sectional shape, but generally circular or rectangular, through which air can flow.
(2) A passage through which services such as water pipes, electric cables or air ducts can be led through a building.

A passage for air or gas flow.

A passageway made of sheet metal or other suitable material, not necessarily leak-tight, used for conveying air or other gas at low pressures.

A series of ducts, conduits, elbows, branch piping, etc. designed to guide the flow of air, gas or vapour to and from one or more locations. A fan provides the necessary energy to overcome the resistance to flow of the system and causes air or gas flow through the system. Some components of a typical system are louvers, grilles, diffusers, filters, heating and cooling coils, air pollution control devices, burner assemblies, volume flow control dampers, mixing boxes, sound attenuators, the ductwork and related fittings.

(1) Date on which a bill, a draft, an acceptance or a loan, or a debt, generally becomes payable. If the debtor does no make the payment at the date on which the debt is payable, it is then said that he defaulted. This date, in the case of bonds, is the date on which the capital must be refunded.

(2) Date on which the contract expires. In the case of the letter of credit, the due date is the last date on which the drafts can be presented for negotiation. When we refer to an option, it corresponds to the last day (American base ) or the only day (European base ) on which the option can be done.

An air suspension of particles of any solid material, usually with particle size less than 100 micrometers.

A dust arrester is a device for catching dust, usually from flue gases. Consequently, much of the dust caught is fly ash.

The relationship between operating time and the resting time of an electric motor.

The pressure of a fluid resulting from its motion when brought to rest on a surface. It is also known as impact pressure, stagnation pressure, and total pressure.