BS 734-1:1973

Co-operating organizations
Foreword
Specification
1 Scope
2 Scale ranges, subdivision of scales and tolerances
3 Adjustment
4 Materials and construction
5 Form
6 Scales
7 Principal dimensions
8 Inscriptions
Appendices
A Suitable hydrometer cylinders
B Thermometer
C Notes on verification of hydrometers
D Testing of British Standard hydrometers for use in
   milk
Table
1 Principal dimensions
Figures
1 British Standard density hydrometers for use in milk
2 Hydrometer scales
3 Cylinder for Nos. 1 and 1A hydrometers
4 Cylinder for Nos. 2 and 2A hydrometers

Hydrometers of two sizes calibrated to be read at the top of the milk meniscus.

This Part of this British Standard specifies requirements for glass hydrometers of constant mass, for use in milk having a surface tension of approximately 45 mN/m, which indicate density in grams per millilitre and which comply with ISO 387, “Principles of construction and adjustment of hydrometers??.

Two sizes of hydrometer are specified, with two scale ranges for each size. The larger hydrometers, designated No. 1 and No. 1A to distinguish between the scale ranges, correspond to the precision types specified in draft International Standard ISO 2449, “Milk and liquid milk products – Density hydrometers for use in products with a surface tension of approximately 45 mN/m??.

The smaller hydrometers, designated No. 2 and No. 2A to distinguish between the scale ranges, are more robust instruments intended to permit the density of smaller samples to be determined.