3 Types
3.1
The clinical thermometers (mercury-in-glass, with maximum device) covered by this Recommendation may be either of the solid-stem type or the enclosed-scale type.
3.1.1
In the case of a solid-stem thermometer, the scale is marked directly on the stem.
3.1.2
In the case of an enclosed-scale thermometer, the scale is marked on a “scalebearing strip” fixed longitudinally behind the capillary tube. The capillary tube and the scale-bearing strip are enclosed in a transparent, sealed tube fused to the bulb and forming a protective sheath.
3.2
The thermometers must include a maximum device which prevents the mercury column from receding solely because of the cooling of the thermometer.