Measurements are taken every 5 m/s starting from 5 m/s up to 35 m/s. The series is repeated twice. The tests are carried out at a nominal ambient temperature of about 17.5 °C, without cooling the wind tunnel.

Two data files are recorded for each measurement. The first file is labeled "_stb" and contains the time record of wind tunnel parameters:

• Time in seconds,

• Wind speed in m/s,

• Relative humidity

• Air temperature in °C,

• Temperature measured by thermocouples in °C. These are placed to the left and right of the conductor.

The sampling frequency for these parameters is 1 Hz. Time histories are recorded for 60 s.

The second file is labeled "_hbm" and contains the signal measured by the force sensors and the axial rotation sensor:

• Time in seconds,

• Force in Newton measured by the horizontal sensor on the left side (left with respect to the wind),

• Force in Newton measured by the left vertical sensor,

• Force in Newton measured by the horizontal sensor on the right,

• Force in Newton measured by the vertical sensor on the right.

• Angle of axial rotation measured by the encoder

• Prestressing of the conductor in Newton.

The zero offset is set at the beginning of each measurement. The data provided is already corrected from zero offset. The sampling frequency of these parameters is 1200 Hz. The measuring time is 60 seconds.

The suffix of each file contains the following information:

• ixxxx = identification number of each measurement

• xxms = wind speed in m/s

• xxpxd = air temperature in the format xx,x °C

• nR or wR = no axial rotation (i.e., fixed conductor) or with rotation in °degrees.

• xxxxHz = sampling frequency in Hz

• std or hbm = wind tunnel parameters or force sensors and axial rotation

If not differently specified, it is intended that the conductor is placed orthogonal to the flow (wind direction 90°)

The measurements are carried out in a similar way to Experiment 1. In these tests the wind speed is kept constant at 10 m/s. The air temperature T varies from the ambient temperature of +15°C to -10°C. The purpose of the tests is to check the stability of the force sensors at negative temperatures.

The first ice experiment of this specimen is carried out at an air temperature T of -10°C. This creates the conditions for dry snow and small accretion after 1 hour exposure.

The second ice experiment of this specimen is carried out at an air temperature T of -8°C. These conditions still generate dry snow and small accretion after 1 hour exposure

The third ice experiment of this specimen is carried out at an air temperature T of -2°C. These conditions generate very wet snow, which is almost a transition to freezing rain. Icicles are observed

The fourth ice experiment of this specimen is carried out at an air temperature T of -4°C. These conditions generate wet snow

The fifth ice experiment of this sample is carried out at an air temperature of -3°C. These conditions produce wet snow and further explore the range between -4°C and -2°C, which is the range of wet snow accretion under the conditions of the experiment. Due to the significant weight of ice in this experiment, the conductor partially rotates during the last part of the test. For this reason, the experiment is repeated (see Experiment 8).

The fifth ice experiment of this sample is repeated at the same air temperature of -3°C. The conductor is fixed at both ends and unable to rotate

The torsional stiffness of the rotating conductor is measured in the wind tunnel. The specific tool is installed at the center of the cable. It allows the application of masses at a given distance (10 cm) from the conductor axis. Rotation is positive when the mass is applied on the windward side. The measurement is recorded continuously in the following order of mass application:

50g, 100g, 200g, 500g, -50g, -100g, -200g, -500g

This experiment lasts 75 minutes and is carried out at a constant wind speed of 10 m/s and air temperature -3°C. The conductor is free to rotate.

The conditions of these tests are the same as in Experiment 10. The only difference is that the conductor is inclined to oncoming wind. While all the other experiments are carried out with the conductor perpendicular to the flow (90°), here the flow is inclined 60° with respect to the conductor.

Handycam scanner

During the deposition tests some snow is taken from a plastic plate located downstream the test bench, to be weighted and used for LWR (liquid water ratio) evaluation by adiabatic method with a calorimeter. The LWR is a non-dimensional number between 0 and 1, which indicates the ratio of the liquid mass of the snow particle compared to the total mass of the snow particle (liquid + solid). Small values of LWR are typical for dry snow, whereas larger values of LWR characterize wet snow. The limit case LWR = 1 corresponds to freezing rain.

The liquid water content (LWC, g/m3) indicates the total mass of the snow particle, both in the liquid and solid state. The LWC is estimated by measuring the mass of the snow collected in a plastic bag after a given period.

For the measurement of density, snow is taken from the plate with a circular cylinder without pressure on it. The volume of snow is known by the shape of the container, it is weighted on a precision balance.