Bod measuring instrumentUsing a dual beam infrared and scattered light photometer for turbidity/suspended solids determination, near-infrared light eliminates color interference, making it a multi range, fast response, self-cleaning online suspended solids monitoring instrument. The principle of measurement: Suspended solids in water quality refer to solid substances that pass through a filter membrane, are retained on the membrane, and dried to a constant weight. We use a vacuum pump for suction filtration to trap suspended solids on the filter membrane. After drying, the amount of suspended solids in the water sample is measured by weight difference.
Bod measuring instrument is an instrument controlled by a microcomputer that measures the concentration of biodegradable organic matter in water samples. A water sample containing saturated dissolved oxygen enters the measuring tank and comes into contact with a biosensor. When there are no biodegradable organic compounds in the water sample, a constant current is generated when the diffusion rate (mass) of dissolved oxygen to the oxygen electrode reaches a constant level. When there is biodegradable organic matter in the water sample, the organic matter is assimilated by microorganisms in the biofilm, and the cellular respiration of microorganisms is also enhanced, consuming some dissolved oxygen and reducing the amount of dissolved oxygen diffused to the surface of the oxygen electrode. When the diffusion speed (mass) of dissolved oxygen in the water sample to the electrode reaches a constant again, a constant current is generated. Due to the quantitative relationship between the difference between these two constant currents and the concentration of biodegradable organic matter in the water sample, the current signal is amplified and analyzed by a microcomputer, and the BOD detection result is directly displayed.
Factors affecting the calibration of bod measuring instruments:
1. Visually inspect the bod measuring instrument cover for any biological dirt or large scratches. Biological pollution can consume or produce oxygen, thereby affecting sample calibration. Large scratches on the paint surface can also affect calibration.
2. Ensure that there are no water droplets on the sensing element or thermistor, and if there are, clean them thoroughly. We also need to ensure a stable ambient temperature for testing operations in the laboratory.
3. Compensating for altitude or atmospheric pressure, many water quality testing instruments now have atmospheric pressure sensors. They will automatically include the air pressure value as part of the calibration program.
4. Compensate for salinity. The salinity of the sample should be tested in advance during testing. To reduce the impact of salinity on sample data.