Owens dust counter platform, slide and accessories
Date: early 20th-mid 20th Century
Inventory Number: 1998-1-0866
Classification: Dust Counter
Subject:
Maker: Blue Hill Meteorological Observatory (1885-present)
Maker: (Slide) Mount Washington Observatory (founded 1932)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
instrument: 17.4 × 14.5 × 4.1 cm (6 7/8 × 5 11/16 × 1 5/8 in.)
case: 5.8 × 17.1 × 21.4 cm (2 5/16 × 6 3/4 × 8 7/16 in.)
Accessories: case; lever; wrench; brass container (grease?); eye piece; 2 metal round bits; slide (1)
Description:
The platform, a slide and some accessories of an Owens dust counter, an instrument for rapidly obtaining samples of airborne dust. The platform, made of metal and brass, is arranged as a vertical column on a round base, with a donut-shaped mirror positioned along the column. The top of the column has an attachment point for an accessory. There is a metal and wooden handle attached to the top of the column.
Particles are drawn through a cylindrical chamber and then passed front of a microscope cover glass. As air passes, dust adheres to the glass. An analysis for quantity and size of the particles on the cover glass is made with the aid of a microscope.
A rectangular, hinged instrument case with a front latch, is lined in purple fabric, and has compartments and support for the instrument and its accessories.
It contains a glass slide with a sample, a metal ring, a cloth ring and a viewpiece, along with an Allen wrench.
Particles are drawn through a cylindrical chamber and then passed front of a microscope cover glass. As air passes, dust adheres to the glass. An analysis for quantity and size of the particles on the cover glass is made with the aid of a microscope.
A rectangular, hinged instrument case with a front latch, is lined in purple fabric, and has compartments and support for the instrument and its accessories.
It contains a glass slide with a sample, a metal ring, a cloth ring and a viewpiece, along with an Allen wrench.
Signedunsigned
Inscribedpaper tag on glass slide with sample: obo #8 / Dec. 24, 1933 / Mt. Wash. / Bottle Test #8 / 50 strokes / 5 pm
FunctionAn instrument for rapidly obtaining samples of airborne dust; a type of dust counter.
Particles pass through a cylindrical chamber and are drawn at high velocity through a narrow slit in front of a microscope cover glass. The fall in pressure due to expansion of the air passing through the slit causes the formation of a moisture film on the glass to which the dust adheres. An analysis for quantity and size of the particles on the cover glass is made with the aid of a microscope. The vacuum required to operate the instrument is developed by an attached hand pump.
Description from the American Meterological Association's website
Particles pass through a cylindrical chamber and are drawn at high velocity through a narrow slit in front of a microscope cover glass. The fall in pressure due to expansion of the air passing through the slit causes the formation of a moisture film on the glass to which the dust adheres. An analysis for quantity and size of the particles on the cover glass is made with the aid of a microscope. The vacuum required to operate the instrument is developed by an attached hand pump.
Description from the American Meterological Association's website
Curatorial RemarksAn air pump and several slides exist in the collection. See 1998-1-0858.
paper in case folded & taped removed. Can't open. cover coming off bottom of case
Blue Hill # 30.
paper in case folded & taped removed. Can't open. cover coming off bottom of case
Blue Hill # 30.
Primary SourcesFirst described in:
OWENS, J. S. (1922). Proc. Roy. Soc. A, 101, 18.
OWENS, J. S. (1922). Proc. Roy. Soc. A, 101, 18.
