Laboratory

Equipment

All the laboratories divide some joint equipment, mainly the equipments laboratory and the glassmaking. Normally, they have at least a hood of laboratory where toxic and dangerous chemicals can be handled without risk. That reduces, and generally, the risk eliminates from inhalation of pollutant gases produced by the reaction of the chemicals. The laboratories have usually a sink to wash the hands. An extinguisher is installed there, to help to extinguish fire in the event of fire. There are also a device to wash the eyes and a shower if the chemicals would run on clothing, the skin or the eyes safe in laboratories of technology and physics, where one does not use a glassmaking, of toxic hood and chemicals. In appendix of the laboratory, there are usually stores where the dry and wet chemicals are stored and where one prepares all the reagents like Acide S, bases S, plug S, graduated solutions and from where one distributes the glassmaking, the small equipment and the protective gears individual of the personnel. In a laboratory of technology or physics, these additional rooms, in general, are used for storage of the equipment and like repair shop.

Often, a room is reserved for the purification of the reagents or, in the case of biochemistry, for the sterilization of the equipment.

The equipment and the orientation of laboratory will depend finally on its goal. The laboratories of university, and in general those of chemical or biochemical analysis contain glassmaking in great quantity.

Like common equipment of laboratory, we have the Centrifugeuse S to separate the solids from the liquids, the Spectrophotomètre S to measure the optical Absorbance of a liquid to a definite wavelength (measurement of the color), Trompe S to provide the Aspiration, and Thermostat S to maintain a temperature fixed and definite. The laboratories of Microbiologie have usually the rooms separated with negative pressure to prevent the entry of Bactérie S harmful. The air passes, in general, by a certain number of filter S and is expelled of the room.

Laboratories designed to treat series of samples, as those intended for the analysis for the ambient conditions or the medical analyzes are equipped with specialized apparatuses automated designed to treat many samples. Research and the experimentation are not a priority in these laboratories; the goal is to give a fast and reliable result.

Work in laboratory

Environmental conditions

Temperature

The normal room temperature is of 20ºC, with some tolerances, depend on the type of experiment or measurement which one wants to carry out. The temperature variations (inside the band of tolerance) must be soft. For example, in the laboratory dimensional Metrology, the temperature variation must be limited to 2ºC/H (while being the interval of tolerance of 4ºC).

Moisture

Normally, it is appropriate that it is weak because it accelerates the oxidation of the metal instruments. Nevertheless, it is considered that the moisture of the laboratory should not be lower than 50%.

Atmospheric pressure

In the industrial laboratories, the pressure must be slightly higher than the atmospheric pressure (25 Pa moreover), to avoid the air intake at the time of the opening of the access doors. In the case of laboratories which present biological risks (handling of infectious agents), the situation must be opposite, i.e. the air which can be contaminated should not be able to leave the laboratory; in this case, the pressure of the environment must be slightly below the atmospheric pressure.

Electrical communication

The variations of tension in the network must be avoided during electrical measurements. These variations of tension can influence the results of measurements.

Dust

It must be controlled. In the laboratories of Interferometry, for example, the presence of dust modifies the behavior of the light crossing the air.

Vibrations and Noise

In addition to disturbing the personnel, the noise and the vibrations can influence the result of the measurements carried out by mechanical techniques. It is the case of measurements made with the instruments which measure the coordinates for example.

Safety at the laboratory

Although the security issues vary according to each case, safety is always a crucial point. Let us quote some good practices:

to always use protections for the eyes (of the glasses of safety);
to use gloves;
to use a protective apron if required;
to avoid breathing or inhaling the chemicals;
to wash the hands with soap lasting at least 20 seconds after a contact with chemicals;
neither to drink nor to eat in a laboratory;
to read and include/understand the procedures before beginning any handling;
to correctly eliminate the chemicals remaining from the operations (the sink is generally not the correct place);
to make sure that the gas distribution is cut before leaving the buildings;
not to try to undertake experiments or handling unless a chemist or a qualified scientist is not present.