一、浊度怎么测
浊度反映水样对光的散射程度，本质是光学指标而非重量指标。主流测量方法是散射光法：光源入射水样，在与入射光成 90° 的方向检测散射光强度。
常见标准有两类：ISO 7027 使用 860 nm 红外光，受水样色度干扰小，适合低浊度到高浊度；USEPA 180.1 使用白光，部分地区的饮用水行业规范要求采用。选型时要确认项目要求遵循哪个标准。
单位常见 NTU（散射浊度单位）、FNU（福尔马肼浊度单位）、FTU。低浊度测量（如饮用水 0.1 至 1 NTU）对分辨率与光学窗口洁净度要求很高。
二、MLSS 怎么测
MLSS（混合液悬浮固体浓度）表示曝气池混合液中悬浮固体的质量浓度，单位常用 mg/L 或 g/L，是活性污泥法的核心控制参数。
在线 MLSS 仪表多采用光学散射/透射原理，通过测量光的衰减或散射强度换算浓度。关键点是：光学法测的是光学信号，必须用现场实际泥样做重量法（烘干称重）比对标定，不同污泥性质的换算关系不同。
典型控制区间（常见经验范围）：曝气池 MLSS 一般控制在 2000 至 4000 mg/L；污泥浓度过高会增加供氧负担，过低则处理能力不足。
三、两者的区别
- 量级不同：浊度常见量程 0 至 100 NTU 或更低；MLSS 常见量程 0 至 10 g/L 甚至更高。
- 标定方式不同：浊度用福尔马肼标准液或标准浊度片；MLSS 需用现场泥样做重量法比对。
- 应用点位不同：浊度多用于出水、沉淀池出水、滤后水；MLSS 用于曝气池、回流污泥、剩余污泥。
- 干扰不同：浊度易受气泡与色度影响；MLSS 易受污泥性质变化、探头污染与气泡影响。
四、选型要点
- 量程与分辨率匹配：测量值最好落在量程的 20% 至 80% 区间，避免用大量程测小值。
- 自清洗方式：污染工况优先选带机械刮刷、气吹或超声清洗的型号；清洁工况可选手动清洗型。
- 安装方式：浸入式、插入式或流通式；曝气池多为浸入式并配探头支架。
- 温度与压力：确认介质温度范围与安装深度。
- 输出与清洗控制：确认是否需要继电器输出来驱动清洗装置。
五、常见干扰与处理
- 气泡：读数偏高或跳变。处理：避开曝气器正上方，加装挡板或消泡措施。
- 探头污染：读数持续偏高。处理：启用自清洗，定期人工擦拭光学窗口。
- 色度干扰：有色废水影响白光法。处理：优先选红外光法。
- 污泥性质变化：MLSS 光学换算关系改变。处理：重新做重量法比对标定。
把测量点位、量程、介质特点与清洗条件告诉我们，我们可以帮您匹配合适的测量方法与安装配置。
1. How turbidity is measured
Turbidity describes how strongly a sample scatters light; it is an optical indicator, not a gravimetric one. The mainstream method is nephelometry: light is directed into the sample and the scattered light is detected at 90 degrees to the incident beam.
Two standards dominate: ISO 7027 uses 860 nm infrared light, little affected by sample colour, and suits low to high turbidity; USEPA 180.1 uses white light and is required by some drinking-water regulations. Confirm which standard the project requires.
Common units are NTU (nephelometric turbidity unit), FNU (formazine nephelometric unit) and FTU. Low turbidity measurement (0.1 to 1 NTU for drinking water) demands high resolution and a very clean optical window.
2. How MLSS is measured
MLSS (mixed liquor suspended solids) is the mass concentration of suspended solids in the aeration tank, usually in mg/L or g/L, and is the core control parameter of the activated sludge process.
Online MLSS meters mostly use optical scattering or transmission, converting light attenuation or scattering into concentration. The key point: the optical method measures an optical signal, so it must be calibrated against gravimetric analysis (drying and weighing) of actual local sludge - the conversion differs with sludge character.
Typical control band (common rule of thumb): aeration tank MLSS is generally held between 2,000 and 4,000 mg/L. Too high increases the oxygen demand; too low reduces treatment capacity.
3. Differences
- Magnitude: turbidity ranges are commonly 0 to 100 NTU or lower; MLSS ranges commonly reach 0 to 10 g/L or more.
- Calibration: turbidity uses formazine standards or turbidity plates; MLSS needs gravimetric comparison with local sludge.
- Location: turbidity is used on effluent, clarifier outlet and filtered water; MLSS in aeration tanks, return sludge and surplus sludge.
- Interference: turbidity is sensitive to bubbles and colour; MLSS to changes in sludge character, probe fouling and bubbles.
4. Selection points
- Match range and resolution: the measured value should sit within roughly 20% to 80% of range; avoid measuring small values on a large range.
- Self-cleaning: for fouling duties prefer mechanical wiper, air blast or ultrasonic cleaning; clean duties can use manual cleaning.
- Installation: immersion, insertion or flow-through; aeration tanks usually use immersion with a probe holder.
- Temperature and pressure: confirm medium temperature range and installation depth.
- Outputs and cleaning control: check whether relay outputs are needed to drive the cleaning device.
5. Common interference and remedies
- Bubbles: high or jumping readings. Avoid mounting directly above aerators; add a baffle or de-foaming measures.
- Probe fouling: persistently high readings. Enable self-cleaning and wipe the optical window periodically.
- Colour interference: affects the white-light method. Prefer the infrared method.
- Change in sludge character: invalidates the MLSS optical conversion. Redo the gravimetric comparison.
Tell us the measuring point, range, medium characteristics and cleaning options and we will match a suitable method and installation.