Measuring nature

1. Torsion balance

For measuring very small forces, for example gravitational or electrostatic forces, by observing the twisting of a thin fiber. It was invented in 1784 by the physicist and engineer Charles-Augustin Coulomb. The unit of electrical charge is named in his honour. (ID 3000.7.23)

2. Voltmeter

For measuring voltage (in volts) in electrical circuits. (ID 4000.39.3)

3. Instrument with two thermometers

Possibly a hygrometer for measuring the humidity of air. (ID 4000.25.25)

4. Sample holder for a Josephson Junction

Similar to the Danish Volt Normal owned by the Institute for Fundamental Metrology, once a part of DTU. It constitutes the standard for volt, the unit for electrical voltage, and is still in use. The sample holder allows for supercooling a Josephson element in magnetically shielded surroundings, enabling the Josephson element to generate an extremely stable voltage. Such an experimental setup has been part of research into quantum electronics and superconducting technology at DTU. (ID 2022.11.2)

5. Hanging scales

Measuring of weight based on the elongation of an internal spring. (ID 4000.48.5)

6. Viscometer

For measuring the viscosity (thickness) of fluids. (ID 4000.31.78)

7. Sulfiric Acid Meter

For measuring the concentration of sulfiric acid. (ID 4000.31.74)

8. An apparatus for angle trisection

Angle trisection refers to the task of dividing an angle into three equal parts. According to the classical rules of construction, this problem cannot be solved using only a ruler and a compass, as proven by the French mathematician Pierre Wantzel in 1837. (ID 4000.25.63)

9. Pressure gauge

A device used to measure the pressure of gases or liquids. The unit is kilograms per square centimeter. (ID 4000.1.422)

10. Tachometer

An instrument used to measure the rotational speed of an engine or a shaft, typically in revolutions per minute (RPM). This particular instrument is dated to around 1920 and has been used for teaching and research at DTU. (ID 4000.1.238)

11. End-point standard

Used for length control. DTU has a similar meter stick in platinum that served as the standard for the entire kingdom of Denmark between 1907 and 1988. Today we use lasers to decide the accuracy of a meter. (ID 3000.63.54)

12. Wattmeter

An analog instrument (in contrast to the modern digital wattmeters) used to measure power in watts. (ID 2018.3.31)

13. Instrument with lens and light source

Possibly a type of goniometer used to measure angles of light through a lens in the practical exercises for civil and mechanical engineers. (ID 3000.29.45)

14. Psychrometer.

Also called a Hygrometer. An instrument used to measure the relative humidity of the air. It consists of two mercury thermometers: a dry thermometer and a wet thermometer. The dry thermometer measures the current air temperature. The wet thermometer contains a cloth that is moistened with water. This thermometer measures the temperature due to the evaporation of water from the cloth. As the water evaporates from the cloth, the thermometer cools down, and the difference between the temperatures on the two thermometers can be used to calculate the relative humidity of the air. The greater the difference between the two temperatures, the lower the humidity, and the smaller the difference, the higher the humidity. (ID 2018.3.79)

15. Ruler on a stand

Used for measuring horizontal displacements, most likely during practical exercises - for example with a pendulum (ID 4000.31.21)

16. Thermo-Ammeter

Dating from around 1939, this instrument was used in the Laboratory of Telegraphy and Telephony for the measurement of electric currents. (ID 2018.3.68)

17. Electroscope

For measuring electrical charge. The tip of the instrument is charged, after which the voltage distributes over the sphere and causes the needle to deflect. The greater the charge, the greater the deflection. (ID 3000.29.32)

18. Vernier scale

With the movable scale it is possible to measure lengths at a higher precision. It was used by students from civil and mechical engineering. (ID 3000.29.240)

19. A set of gilded weights

These weights were used for high precision measurement of weight. The gilding helped prevent oxidation and corrosion, which could affect the accuracy of measurements. (ID 3000.63.14)

20. A set of gilded weights

These weights were used for high precision weighing. The gilding helped prevent oxidation and corrosion, which could affect the accuracy of measurements. (ID 3000.63.30)

21. A set of gilded weights

These weights were used for high precision weighing. The gilding helped prevent oxidation and corrosion, which could affect the accuracy of measurements. (ID 3000.63.25)

22. Measuring tape

Used in exercises by students from civil and mechanical engineering. (ID 1000.1.37)

23. Aneroid Barometer

Mechanic, nonliquid. Used for measuring atmospheric pressure and altitude It was used in the laboratories in Sølvgade, Copenhagen, when DTU resided there. (ID 4000.1.181)

24. Goniometer

Used to measure angles of light reflection in research and teaching in the first half of the 20th century. (ID 4000.1.149)

25. Balance scale

A student project from around 1950. (ID 3000.91.49)

26. Weston element

A voltage standard to calibrate voltmeters. It has a known, stable voltage at 20 degrees celsius. (ID 4000.1.256)