Immediately after WWII the Mettler company of Switzerland developed and introduced
a revolutionary design of mechanical balances: Only one pan was now visible to the
user, and all weights were included in the case and operated by knobs from the outside.
Furthermore the so-called substitution principle was applied for the weight-loading.
All other balance makers followed suit, and these are Stanton's variations on the
theme. These balances also represent the last innovations introduced before the merger
In more general terms, these designs represent the last word in commercial mechanical
balances for chemical/analytical applications. Very soon electronic balances would
appear on the scene, gradually displacing mechanical ones in manufacture and use.
The Ultramatic model. Single-pan balance of 200 gram capacity, resolving to 0.1 mg
on an optical chart. Fully weight loaded by external coloured dials, applied weight
digitally displayed behind a glass screen.
The Ultramatic CL1, which introduced the constant-load (substitution weighing) method,
as per Mettler's design. Sectioned model from the Science Museum.
The Unimatic model, again using the constant-load principle. There were a number
of sub-models in this range, each with different resolutions and special features,
such as a pre-balance which gave a weight estimations prior to "dialling in" the
knob settings. Typically 200 g capacity, and up to 0.01 mg resolution. The SN1 as
displayed only has 1 mg resolution, a student model.
A Unimatic CL41, the standard workhorse of the single-pan range. 200 g capacity,
0.1 mg resolution.