Turbidity Meter Works Is What?

- Feb 16, 2018-

Turbidimeter instrument works

1. The instrument uses integral sphere turbidity determination principle:

A parallel beam of light propagates in a transparent liquid. If there is no suspended particles in the liquid, the beam will not change direction when propagating in a straight line. If there is suspended particles, the beam will change its body when it encounters the particles Or not). This forms the so-called scattered light. The more particles (turbidity), the more serious the scattering of light. Turbidity is measured using an instrument called a turbidimeter. The nephelometer emits light that passes through a length of the sample and detects how much of the light is scattered by the particles in the water from a direction 90 ° to the incident light. This method of measuring scattered light is called scattering. Any true turbidity must be measured this way. Turbidimeter both for field and laboratory measurements, but also for all-weather continuous monitoring. Turbidimeters can be set up to alert you when measured turbidity levels exceed safety standards.

As shown in the figure,the incandescent light emitted by the light source is condensed on the pinhole after being condensed by the condenser lens. The collimated objective lens turns the light emitted by the pinhole into a bundle of parallel light with good parallelism and exits. The parallel light is decomposed into Through the light and scattered light (respectively recorded as Tp) and Td), and into the integrating sphere. The inner wall of the integrating sphere is equipped with two light-sensitive elements that receive transmitted light and scattered light, respectively. Through the optical signal and scattered light signal amplified by the circuit and processed by the following formula:

Turbidity = K * Scattered light flux / transmitted light flux

= K × Td / Tp

K: Proportional constant.

2. The measurement value is not affected by the liquid color:

Assuming that the sample is colorless, the incoming light flux into the liquid is 10 and the outgoing light flux is also 10. The relationship between the outgoing flux, the scattered flux and the parallel flux is (regardless of reflectance, absorption, etc.) of the cuvette:

l0 = Tp + Td

If the sample with color, the incident light into the liquid will be part of the absorption, set the liquid transmittance T, then the luminous flux l0, scattered light flux Td, and the parallel luminous flux Tp, the relationship.

l0, = T × l0Tp, = T × TpTd, = T × Td

That is, their intensity decays by the same factor T, either through light or scattered light.

Turbidity measurements will remain unchanged at this time:

Turbidity = K * Scattered light flux / transmitted light flux

= K × Td, / Tp, = K × T × Td / T × Tp

= K × Td / Tp

The company specializes in producing and selling a variety of turbidimeters, welcome to consult the needs of the procurement.