Geosciences

Water purification by filtration with active carbon

Principle

Active carbon is a good absorbent and as such is excellent when used as a filter. During water treatment, for example, active carbon filters are used to remove pesticides and detergents (soap and washing-up liquid). The cleansing of water can be demonstrated im ...

The phases of the moon

Principle

This experiment, which should be carried out in a completely darkened room, makes great demands on the students' ability to concentrate and observe.
 

Task

What causes the phases of the moon? Investigate ...

Altitude measurement on a trail

Principle

The altitude profile of a hiking trail or route to school can be measured during a school trip or as an exercise for the students. The altitude profile can also be used to demonstrate that the atmospheric pressure decreases when the altitude increases ...

Measuring the height of a tower

Principle

The weather sensor can be used to determine the height of a tower as a function of the change in air pressure with the aid of the barometric formula.

24-hour weather observation

Principle

The compact Cobra4 Weather multisensor makes for fitting out your own weatherstation with little means. It allows the relations between air pressure, humidity and temperature, and also brightness, to be made understandable. Fluctuations over a period ...

Weather observation with the Cobra4 Mobile-Link

Principle

The compact Cobra4 "Weather" multisensor can be employed as a simple means to setup a weather station, which can then be used to explain the relationship between the air pressure, humidity, temperature, and the light intensity. The measurement combina ...

Terrain mapping

Principle

The drawing of maps is one of the favourite tasks of the students during geography lessons and of a high didactic value. The altitude measuring function of the Cobra4 Sensor-Unit "Weather" is a user-friendly tool which provides altitude values so that ...

Comparison of soil and air temperatures in the course of a day

Principle

How does the temperature of the air affect the temperature of the soil in the course of a day?

Examination of the structure of NaCl monocrystals with dif-ferent orientations

Principle:
The spectra of the X-rays that are reflected with various different orientations by NaCl monocrystals are analysed. The associated interplanar spacings are determined based on the Bragg angles of the characteristic lines.

Tasks:

X-ray investigation of cubic crystal structures / Debye-Scherrer powder method

Principle:
When polycrystalline samples are irradiated with X-rays a characteristic diffraction pattern results. These Debye-Scherrer reflections are photographed and then evaluated.

Tasks:

1. Debye-Scherrer photographs are ...

X-ray investigation of hexagonal crystal structures / De-bye-Scherrer powder method

Principle
A polycrystalline zirconium foil is irradiated with X-rays. The resulting Debye-Scherrer reflections are photographed and then evaluated.

Tasks

1. Take Debye-Scherrer photographs of the zirconium sample.

X-ray investigation of crystal structures / Laue method

Principle:
Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X- ...

Debye-Scherrer diffraction patterns of powder samples withthree cubic Bravais lattices (Bragg-Brentano-geometry)

Principle:
Polycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the ...

Debye-Scherrer diffractions pattern of powder samples with adiamond structure (according to Bragg-Brentano)

Principle:
Polycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the ...

Debye-Scherrer diffraction patterns of powder samples with ahexagonal lattice structure

Principle:
A polycrystalline powder sample of zinc is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice p ...