Pyxis LT-630 Series Self-Wiping Turbidity Sensors and LT-635 TSS Sensor

The Pyxis LT-630 series (LT-631, LT-632, LT-633) and the LT-635 are submersible inline sensors with a stainless steel body and a motorized wiper arm that cleans the lens automatically; the LT-63X measures turbidity and the LT-635 measures suspended solids (TSS). Both clean the lens surface at regular intervals, which prevents drift caused by air bubbles and sediment, so they work with low maintenance in dirty media such as raw water, wastewater and sludge lines. Mikron Proses (Üsküdar, Istanbul) provides application consulting on choosing the model and the mounting method for your process.

Turbidity · Suspended solids · Self-wiping sensors → Send us your requirement

For the measurement background, see the guide on online turbidimeters. For ultra-low turbidity with an auto-brushing flow tee, see the IK-73X PLUS analyzer.

LT-63X series: submersible turbidity measurement

The LT-631 (0-500 NTU), LT-632 (0-1,000 NTU) and LT-633 (0-4,000 NTU) are three range options on the same platform. Measurement uses scattering with dual infrared light sources and is ISO-7027 compliant. Accuracy is ±2 NTU or 3% of the value, precision is ±2 NTU or 2% below 100 NTU and ±10% of the reading above, the lower detection limit is 0.5 NTU, resolution is 0.1 NTU and response time is T95 <12 seconds. The sensor automatically compensates for disturbances from flow fluctuation, climate change, color change or turbidity change, and when kept clean it is stable to <0.1 NTU for up to 1 year without calibration.

LT-635: suspended solids on the same platform

The LT-635 uses the same body and wiper mechanism but a different measuring principle: it measures the absorption of 850 nm infrared light as it passes through the sample, unlike the scattering method of the LT-63X. The range is 0.00-30 g/L (0-30,000 mg/L), precision is ±0.1 g/L or 5% of the value and response time is T95 <10 seconds. Calibration is application-specific, against a sample tested by gravimetric suspended solids analysis. The LT-635 is used in aerobic and anaerobic basins and digesters of activated sludge wastewater processes and for sludge bed level detection in clarifiers and thickeners; typical wiper life is 12-18 months at an average of 10 cycles per hour.

Body, mounting and protection

Both sensors have a 316L stainless steel body and wiper arm, a PTFE wiper blade and IP-68 protection. The LT-63X is 254 mm long and the LT-635 is 288 mm long, both with a 57 × 57 mm cross-section; the LT-63X weighs 1,530 g. They can be mounted in three ways: fixed submersion on a 3/4-inch MNPT thread, hanging submersion on a chain or rope using the lifting ring (for sludge bed profiling), or inline in a by-pass flow line using the ST-008 tee. The manufacturer states that the ST-008 tee is designed for the LT-632 and LT-633, and allows operation at up to about 3.1 bar when installed in it.

Outputs and wireless calibration

Both sensors run on 22-26 VDC at 6 W and provide an isolated 4-20 mA analog output and an isolated RS-485 Modbus digital output at the same time. With the MA-CR Bluetooth/USB adapter, the uPyxis mobile or desktop app gives live graph monitoring, diagnostics, wiper timing programming and wireless calibration. The LT-63X is calibrated with a formazin calibration standard or a process sample of verified turbidity; the LT-635 is calibrated with a field sample tested by the gravimetric method.

Ordering and accessories

The LT-631 (P/N 53249), LT-632 (P/N 53250) and LT-633 (P/N 10002) turbidity sensors and the LT-635 (P/N 53251) suspended solids sensor are separate part numbers. The standard package includes a sensor with a 10 m fixed cable, a 1.5 m flying lead cable, an MA-CR Bluetooth adapter and an MA-NEB USB adapter. Optional accessories include the ST-008 stainless tee, the MA-120-B submersion mounting bracket and the MA-50CR / MA-100CR extension cables. Send us your requirement and we will select the model and mounting method together.