China Turbidity Tester Manufacturers & Factories

The difference centers on the light source emitter wavelength and physical interaction with water chemistry. ISO 7027 uses a monochromatic Near-Infrared LED at 860 nm (±30 nm). Because water organic color components (such as humic and fulvic acids) do not absorb light in this near-infrared region, ISO 7027 is essentially immune to sample dissolved color interferences. It is the dominant standard across Europe, Asia, and international wastewater networks.

Conversely, US EPA 180.1 mandates a tungsten-filament incandescent lamp operating at a broad color temperature of 2200K–3000K (visible spectrum 400–600 nm). The short visible wavelengths scatter more efficiently off ultra-small sub-micron particles (<0.1 NTU), making it exceptionally sensitive for finished drinking water distribution compliance in North America, but susceptible to optical absorption if the fluid contains dissolved color.

In activated sludge, industrial effluent, or warm aquaculture RAS, optical sapphire lens surfaces attract bacterial biofilm, algal colonization, and inorganic scale (calcium/iron precipitates) within 24 to 72 hours. This film attenuates light beams and mimics high turbidity (drift).

BOQU’s ZDYG-2088-01QX features an integrated, magnetically sealed mechanical silicone wiper blade. Configurable via software to cycle at programmable intervals (e.g., every 15, 30, or 60 minutes), the wiper sweeps across the optical sapphire window, physically scraping away biomass. When not in motion, the wiper parks 180° away from the optical beam path so measurement is unaffected.

Yes, but with an important scientific caveat: turbidity measures optical light scatter (in NTU or FNU), whereas TSS and MLSS represent physical gravimetric mass concentration (in mg/L or ppm). Because different suspended particles have different shapes, refractive indices, and grain sizes, there is no universal constant between NTU and mg/L.

BOQU online transmitters incorporate multi-point empirical curve fitting algorithms. Plant operators run standard gravimetric laboratory filtration tests (EPA Method 160.2) on actual grab samples and enter the corresponding mg/L values into the transmitter alongside the optical sensor’s raw scatter data. The internal processor constructs a multi-segment calibration curve, delivering precise TSS readouts up to 30,000 mg/L.

When measuring low-range turbidity (<1.0 NTU), the primary source of error is entrained micro-bubbles. Tiny air bubbles scatter light identically to suspended mineral colloids, causing false high-turbidity spikes.

To eliminate this, low-range sensors must be installed inside a dedicated flow cell equipped with an internal baffle bubble trap and steady laminar flow regulator (typically 300 to 700 mL/min). The sample line must be connected to the bottom inlet and vented to an atmospheric drain. Furthermore, the flow cell interior should have a matte black, non-reflective coating to prevent stray light reflection from impinging on the photodiode.

Shanghai BOQU Instrument Co., Ltd. is an authentic original equipment manufacturer (OEM/ODM). Established in Shanghai in 2007, our company operates 4,632 square meters of production space across our Kangqiao Town sensor laboratory and Lingang industrial workshops.

We design our own sensor optics, blow specialized high-temperature glass, populate electronic printed circuit boards, author internal DSP firmware, and conduct 48-hour environmental burn-in calibration. Overseas buyers can audit our facilities in person or through live 360-degree interactive VR factory tours.

BOQU instruments offer modern industrial communication capabilities. Our standalone smart digital sensors output RS485 Modbus RTU telemetry directly from the waterproof cable head, operating at standard 9600 or 19200 baud rates. This allows system integrators to daisy-chain up to 32 sensors directly into a central PLC or IoT wireless gateway without purchasing expensive dedicated controllers.

When paired with BOQU wall-mounted or panel transmitters, systems provide isolated 4-20mA analog current loops (active or passive loop powered), programmable SPDT mechanical relay contacts (for upper/lower alarm triggers or dosing pump actuation), and optional 4G/NB-IoT wireless cloud connectivity.