- Seen : 209 View
Calibration gases, like other gases, have specific categories and groups, each of which belongs to a specific group. In fact, calibration gases can be divided into two separate categories. The first group is zero calibration and the second group is extensive calibration.
Zero gas is a group of calibration gases in which there is no flammable gas. This gas is used when the gas analyzer is calibrated with a different gas than what it is supposed to detect. To make the understanding of this explanation concrete, it is better to give an example, the zero calibration gas of pure nitrogen is used for oxygen or carbon dioxide, and this is how the zero point for the gas is identified.
The next group of calibration gases is a more advanced type called extended calibration gases. In this type, a specific concentration of the identified gases is used to calibrate the analyzer. Sales of calibration gases are produced and supplied according to customers' requests.
Preparation of calibration gas
Calibration gases are produced in different ways:
The first method of producing calibration gas is using permeation tubes. In this method, the liquid gas flow is controlled by the temperature in the pipes, thus it can produce compounds with low concentrations. It is easy to carry and move these penetrating tubes. It should be mentioned that this type of calibration gas is used for toxic detectors that react to the lowest concentration. The use of penetrating tubes is not suitable for high concentrations.
Another method is to prepare standard calibration gas by injection. In this method, gas enters the flow through a syringe, pump or any similar tool. In the production of calibration gas in this way, the concentration can be changed and reduced from a few percent to a few ppm. Liquid gas is evaporated before injection.
The third method in preparing standard calibration gases is the evaporation method. In this method, the carrier gas is passed through the target gas which is in liquid state.
Saler Company Information
