Accession No

5199

Brief Description

naniwa hytester in small plastic box, 2/2 20th C

Origin

Maker

Naniwa

Class

physics

Earliest Date

1950

Latest Date

1998

Inscription Date

Material

glass; metal (lead); paper; plastic (perspex, foam); organic (cotton wool)

Dimensions

length 80mm; maximum diameter 18mm box length 94mm; breadth 74mm; thickness 23mm

Special Collection

Provenance

Donated by Anglia Polytechnic University (now Anglia Ruskin University), East Road, Cambridge, on 07/01/1998.

Inscription

‘NANIWA HYTESTER’ (scale)

Description Notes

Glass tubular object, neck descends in to a horned glass barrel below which is stored lead shot. Neck contains paper scale. Two scales present: one marked ‘A’ and numbered 3, 5, 7; the other marked ‘S’ and divided 5, 7, 9. The object is for testing the freshness of photographic fixer. Scale ‘S’ is for Sodium thiosulphate fixer and scale ‘A’ for Ammonium thiosulphate fixer; the numbers represent minutes required to place the photographic paper in the fixer to complete fixing of the image. A red band around the top of the scales indicates the need to make fresh fixer solution. The hytester works on the principle of the difference in specific gravity between water and hypo or fixer solution. The higher the hytester floats, the fresher the fixer.
Perspex box lined with green foam

Condition good; complete.

References

Events