Purifying water treatment industry in the process of production for turbidity meter and the choice of display instrument selection scheme

Turbidity measurement of turbidity is the water turbid degree measure, also is the fine dispersion of suspended particles in water, make water to reduce the degree of transparency. Turbidity meter is a measuring instrument for water turbidity degree, it is mainly used for monitoring and management of water quality. Water treatment works for residents living water and industrial water supply, water supply quality directly related to people's health, safety, and food, brewing, medicine, textile, printing and dyeing, electricity, and so on all walks of life to normal production and product quality. Turbidity is an important quality index, so the choice of turbidity meter is particularly important. Turbidity meter can be divided into visual turbidity meter and optical turbidity meter two kinds big. Photoelectric turbidity meter is its USES can be divided into process monitoring ( Continuous determination of) Turbidity instrument and laboratory ( Including portable) Turbidity meter, its design principle and can be divided into the transmitted light turbidity meter and scatter light turbidity meter. Due to light scattering turbidity meter for low turbidity of water has a high sensitivity, high accuracy, the relative error is small, good repeatability, chroma does not display the turbidity of water, and the scattering light and incident light intensity than a linear relationship, so in September 1992 the world health organization (who) published the drinking water quality standards, regulations, will scatter light turbidity meter as measurement instrument. At the same time, & other; Water supply industry throughout 2000 & technology development planning; Is specified in a class of water pipe network water turbidity index of 1 ntu. After the filter water and effluent of measurement, generally USES 1720 - d ( Originally 1720 c) Series of turbidity meter. When using water continuously flows into turbidity meter, through to take off the bubble to emptying air bubbles in water, and then into the stele of the turbidity meter, rise to measuring room and spilling over the edge into the drains. Beams down from sensor head components in projected onto the turbidity instrument in the main body in the water samples, submerged in water samples of photocell measuring water suspended solid 90 & deg; The direction of the scattered light, the amount of scattering light is proportional to the turbidity of water. 1720 d don't need to use the sample pool, can reduce the stray light, so improve the measurement accuracy. The accuracy of 1720 - d: 0 ~ 40 within ntu for & plusmn; Within the scope of 2%, 40 ~ 100 ntu for & plusmn; 5%, resolution of 0. 001 ntu, the response time of 75 s. Measuring the turbidity of water after filtration meter installed on filter standing inside the pipe rack, hanging or cabinet can be used, the factory water measurement generally between water pump room set up water quality instrument, puts turbidity meter and other water quality testing instrument instrument room, then drew signal to monitor. Although 1720 d measuring range of 0 ~ 100 ntu, but good to the measuring filter before the water, because although optical can detect 100 ntu, but in production use will bring a lot of inconvenience. Measurement of source water and filter water before use SS6 series more surface scattering turbidity meter, it is shot in the liquid surface of the beams, the determination of scattered light from the liquid surface, to avoid the optical system, direct contact with water pool eliminates the cleaning circulation signal loss. SS6 series of measuring range of 0 ~ 9999 ntu, general surface water source of water in this range. The accuracy of it within 0 ~ 2000 ntu for & plusmn; Within the scope of 5%, 2000 ~ 9999 ntu for accuracy & plusmn; 10%. The turbidity meter sampling points should be selected and combined closely with the process of * *, the selection of typical points, sampling hole is good not to open at the top of the the sampling pipe, avoid smoking pipes bubbles and progress here and will affect the turbidity meter measurement accuracy, the extraction of water use of small sampling pump samples, ensure the sampling tube has a certain velocity, not easy on the inner wall of the pipeline scaling. The sampling pipe diameter should be determined according to the sampling instrument total water demand. Selection of display instrument of the general project of water treatment works more intelligent display instrument, the function is all ready, able to digital signal processing, realize the control function, and measurements with LCD display, easy to operate, can save the data, has the self-diagnosis function. Although after connect with computer systems, it fully exert the advantage of no, and replaced by a computer system, but in the current construction of water treatment works, using intelligent display instrument as not in the computer system debugging of commissioning phase or failure of auxiliary instrument, can meet the requirements of field control, display, such as the checking instrument, we often see a paper recorder, blue screen or color screen multichannel paperless recorder, etc. , basically can support 4 - all these display instrument 20 ma and pulse signal input, high-end products can achieve universal input, support can see on market at present most of the signal output type. In some cases, at the same time, need according to local and remote transmission, the unfavorable signals, and the signal distributor should be adopted, namely 1 road input, two lines of output, output all the way to send display instrument, one output to the input of PLC, such as common WS15242.