002.381.Idrija

Idrija Mercury Heritage Management Center, Bazoviška 2, SI-5280 Idrija

Public

Republic of Slovenia

/

Daily life

In a wooden box, there are five contact thermometers, which are installed on foam brackets, which serve as protection. The contact thermometer is a one-piece round oblong pipe. The bottom part is slightly narrowed and semicircularly fused and filled with mercury. The upper part is closed with a plastic module, attached as a holder. The electric plug is at the side. On the module, there is also a screw. In the thermometer there are two measuring scales, both with the range from 0 to 50°C. The lower one is the same as in all other thermometers, the upper one is equipped with a wired platinum conductor. The latter is derived from the lower capillary with mercury.

Length 47.5 cm, width 21.5 cm, height 5 cm.

Glass, mercury, plastic, platinum, wood.

1960s

Manufacturer information is not known.

The contact thermometer is used for switching the electric circuit, in dependence of the temperature, on and off. In the capillary with mercury, there is a platinum wire fused on the lower part of the contact, and another one above it. Due to the thermal expansion when the temperature is raised, the mercury in the capillary expands, rises and the electrical circuit is established between the contacts. When the system cools down and the mercury level in the capillary is lowered, the contact is interrupted and consequently the circuit is also interrupted.

The set of contact thermometers is being preserved, secured and presented as important mining heritage of Idrija with exceptional universal values. It is a part of the CUDHg Smelting Collection. Visitors can view them within the permanent museum display “From Ore to Mercury Drops” in the Hg Smelting Plant, which represents the characteristics and the versatile use of mercury in science, technology, medicine, culture and every day life. Within the exhibition, the object is placed in the thermal expansion segment and it represents the usefulness of mercury for technical devices.

University of Ljubljana, Faculty of Chemistry and Chemical Engineering, Večna pot 113, SI-1000 Ljubljana.

Hg Smelting Plant (From Ore to Mercury Drops), Arkova 50, SI-5280 Idrija

The set of contact thermometers is well preserved. Additional interventions are not necessary. Security of the premise is taken care off.

good

Regular seasonal maintenance.

- CUDHg Inventory Book.

Mestni muzej Idrija

Miha Kosmač

16. 3. 2018

Never