Graticules Ltd. Measuring Scales
A range of versatile portable measuring instruments which combine the accuracy of finely divided glass scales with the simplicity of magnifiers. These are ideal tools for the inspection bench, drawing office, workshop, and laboratory, especially the microscopy laboratory, when measurements exceeding the capacity of a magnifier on its own are needed. The measuring scale needs to be in close contact with the flat specimen.
The instrument is built around a glass measuring scale, an accurate separation of the distance in vacuum deposited chromium on the underside of a 6 mm thick rectangular cross-section of glass. This is mounted in a metal frame finished in white enamel with sliding magnifiers which can be focussed individually on the critical points of the specimen to be measured. The slides run on stainless steel bearing rods.
The instrument is placed with the measuring scale in close contact with the specimen to be measured. One magnifier is positioned over one end of the length, the second magnifier at the other end. When only one magnifier is available (for example, the smallest model), it must slide from end to end.
If one of the data points corresponds to zero on the scale, the length will be that which is read off at the other end. However, it may be easier to align the scale with the length to be measured and to then determine the length from the two readings.