Problems to pay attention to when starting up
1. Before starting up, turn on the power after returning all the knobs on the instrument panel to zero. Turn on the low voltage first and then the high voltage when starting up. The opposite is true when shutting down.2. The element lamp needs to be preheated for 30 minutes, and the lamp current is slowly increased from low to an appropriate value to ensure that the light is stable before being used for measurement. After the element lamp is turned off, it should be cooled in the original position for more than 5 minutes before taking it off. Ensure that the elements in the cathode part of the lamp that are liquid due to the high temperature are solidified. Otherwise, the service life of the element lamp will be shortened. To keep the lamp window clean, if there is dirt, gently wipe with lens cleaning paper.
3. The two gas sources should be at a proper distance from the instrument. When igniting, turn on the auxiliary gas first, and then turn on the combustible gas. When shutting down, turn off the combustible gas first, and then turn off the auxiliary gas. Finally vent the air compressor. During the combustible gas combustion, the operator cannot leave. Check the pipeline frequently to prevent leakage.
4. Ordinary sprayers cannot spray high-concentration fluorine samples.
Problems that need to be paid attention to during operation
1. During the detection process, the combustion head cannot be burnt empty, and deionized water or blank water must be sprayed in. In order to prevent backfire of combustible gas, a water seal must be added to ensure safety.2. During the measurement process, the zero point of the instrument may drift, and it must be checked continuously. If drift is found, the zero point must be adjusted again.
3. The element lamp has a shelf life, so everyone must pay attention to it when buying and storing.
4. All atomic absorption spectrometers used should meet the following indicators.
a. Detection limit: The detection limit of potassium ions for the measured water sample should be less than 0.05mg/L
b. Linearity of the working curve: the ratio of the slope in the upper 20% concentration range of the working curve to the slope in the lower 20% concentration range should not be less than 0.7.
c. Minimum accuracy requirements: the standard deviation of the 10 absorbance of the highest concentration in the working curve should not exceed 1.500 of its average absorbance; the standard deviation of the 10 absorbance of the lowest concentration standard solution should not exceed the average absorbance of the highest concentration standard solution Of 0.5%.
Under the premise of satisfying the analysis conditions, reducing the lamp current can reduce the noise of the instrument. Extend the life of the lamp.
5. An exhaust device should be installed above the burner of the instrument.
The above are the issues that need to be paid attention to when using flame atomic absorption spectrophotometer to detect water quality.
