The manufacturing method of glass thin tubes is difficult, and there are glass thin tubes with different inner and outer diameters depending on the manufacturing lot.

Therefore, glass thermometers with different lengths of temperature notation are produced.
The temperature error (allowable crossing) is ± 1 per 1 degree scale thermometer according to JIS B 7411.
The maximum temperature difference is 2 ° C, but it is within the allowable crossing range.