General Information

Serial #

350-1045

Part Number

1

Total Parts

1

AKA

Digital pressure monitor

Patents

N/A

General Description

metal casing and parts/ synthetic casing front, controls, power cord, parts/ leather? handle

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

45.5 cm

Width

22.2 cm

Height

22.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Meteorology

Category

Miscellaneous

Sub-Category

N/A

Manufacturer

AKA

GARRETT

Country

Canada

State/Province

Ontario

City

Rexdale

Context

Country

Canada

State/Province

Ontario

Period

1970's -1990's

Canada

Part of a large collection of meteorological instruments acquired from the Meteorological Service of Canada (previously Atmospheric Environment Service) by the CSTM since 1967. MSC is the government agency responsible for collecting and disseminating meteorological data and forecasts in Canada. It was founded in 1871 in Toronto where it is still headquartered. The MSC was originally on the University of Toronto downtown campus but moved to Downsview in 1971 on land owned by UofT. The headquarters houses laboratories, research facilities and calibration and instrument maintenance facilities (now largely contracted out).

Function

An instrument used to provide direct air pressure readout in standard units, used in the calibration of pressure rmeasuring instruments.

Technical

An example of a precision calibration instrument used in a laboratory to verify air pressure reading instruments. The core component of the instrument is a resonant cavity pressure transducer. The solid state pressure sensing element is made of Ni-Span-C, a nickel-iron-titanium-chromium alloy. Extremely high temperature stability is achieved by using this alloy because its elasticity variation with temperature is balanced by its dimensional changes. The resonant cavity is made of double walled construction with the interspace evacuated to absolute vacuum. The input pressure ( that which is to be monitored) is introduced into the cavity: the wall is stressed by the differential between input pressure and absolute vacuum. Since the resonant frequency of the cavity is a function of its stress, the transducer generates an ac signal the frequency of which is proportional to the input pressure. The frequency output of the pressure transducer is converted by digital logic into a direct reading six digit display. As indicted by its detailed model number (see Details) this version of the AFTS-23 has a pressure and temperature range of zero to 32 inches HgA Class III. It's output signal is non-servoed and it has no external read-out. This model has one pressure input and accepts either air or nitrogen as the pressure medium It is capable of absolute display only and its units of display included 0 to 100 inches Hg, 0 to 49 PSI, or 0 to 3300 millibars (Refs. 1-2) In 1936, Cliff Garrett founded a company which came to be known as Garrett AiResearch or simply AiResearch. Garrett AiResearch designed and produced a wide range of military and industrial products for aerospace and general industry (Ref. 4).

Area Notes

Unknown

Details

Markings

raised black lettering on front reads 'DIGITAL PRESSURE MONITOR/ AFTS-23' with raised Garrett logo/ labels on back read 'DIGITAL PRESSURE MONITOR/ PART NO. 628168-1-1/ SERIAL NO.0350-1045/ MODEL AFTS 23-1-1-1-6-2/ RATING 115YAC/ 50/60 HZ/ SINGLE PHASE 1 AMP/ [logo] GARRETT MANUFACTURING LIMITED/ 255 ATTWELL DRIVE . REXDALE, ONTARIO, CANADA' AND 'MODIFICATION/ E M11 M12/ M10/ Garrett Manufacturing Limited'/ label on front reads ‘GOVERNMENT OF CANADA/ METEOROLOGICAL BRANCH/ INSTRUMENT DIVISION/ CALIBRATION UNIT/ C16-203 035C-1045/ DEPARTMENT OF TRANSPORT/ 'paper labels on various parts reading 'G" and 'MARCH 22 1985' with white stamped 'MARCH 22 1985' on back Black typewritten lettering on label on casing top reads 'This barometer, Garrett AFTS #0350-1045/ should never be left exposed directly to room air, except for moving./ It should always be connected to the network of rubber hose, and that network should always be kept/ closed, except when installing test sensors./ Failure to follow this guideline will allow the sensing element/ to be exposed to fluctuating humidity levels, resulting/ in changes to the calibration'.

Missing

appears complete

Finish

textured black painted casing/ black and grey casing front/ yellow controls on front, grey on back/ grey power cord/ black strap with plated metal fasteners/ white paper labels

Decoration

N/A