Howard F. Fortescue Ltd. is registered in England and Wales; Company No. 6237839.

HFF has more than 25 years experience in the Optical Disc Industry.

Volume Units

Volume

Basically, measure (or convert) everything in litres and its subdivisions and most things are easy and OK.

Gallons are a bit of a confusion:

1 US Gallon (strictly US liquid gallon) = 3.785411784 litre

1 Imperial (UK) Gallon                        = 4.54609         litre

UK Gal / US Gal                                 = 1.2009  i.e. 20% more

or 1 US Gallon = 0.83 UK Gallons, nearly 20% less.

For anyone interested in the derivation:

1 US Gallon = 231 cubic inch

1 inch = 2.54 cm

1 litre = 1000 ml = 1000 cc (cubic centimetre)

1 Imperial Gallon is the volume of 10 pounds of water at 62^oF.

Gallons are no longer legal in the UK, pounds are only used in shops (and then have to be accompanied by kg values) and all serious scientific or engineering work has been done in ^oC since I was at school.

Water

Water in SI units is great:

1 cc has a mass of 1 g

1 litre has a mass of 1 kg

1000 litres has a mass of 1000 kg = 1 tonne (metric ton)

A Tonne is fairly close to other old Ton.

1 old imperial Ton = 1016.0469088 kg

1 US (Short) Ton = 907.18474 kg

It's best to keep to SI units for simplicity and accuracy.