Looking for a quote or to discuss your needs?
You can also review the documentation for technical details and purchasing information.
LT-635 Suspended Solids Sensor
- Product Details
- Specifications
- Wastewater Treatment
LT-635 Suspended Solids Sensor
Total Suspended Solids from 0 to 30,000 mg/L
The Pyxis LT-635 is a submersible sensor that measures suspended solids continuously, from 0 to 30 g/L (0 – 30,000 mg/L). It is made for wastewater treatment: activated sludge basins, digesters, and finding the sludge bed in clarifiers and thickeners.
A wiper cleans the optics on a timer, so bubbles, slime and sludge do not build up on them. The transmitter is built in, with isolated 4–20 mA and RS-485 Modbus outputs for a controller, PLC or DCS, and the sensor can be set up, calibrated and checked over Bluetooth® with the uPyxis® app.
Measures Light Absorbed, Not Light Scattered
A turbidity sensor such as the LT-630 series reads the light scattered by particles and reports in NTU. The LT-635 instead shines 850 nm infrared light across a gap through the sample and measures how much is absorbed, giving a reading in suspended solids. It is calibrated against a gravimetric TSS result from your own process water, so the sensor follows the measure your plant already reports.
LT-635 Specifications
| Item | LT-635 |
|---|---|
| Part Number | 53251 |
| Parameter | Suspended solids / total suspended solids (TSS) |
| Measurement Range | 0.00 – 30 g/L (0.00 – 30,000 mg/L) |
| 4–20 mA Output Scale | 0 – 30 g/L |
| Unit | ppm (as SS or TSS) |
| Resolution | 0.1 g/L |
| Precision | ±0.1 g/L or ±5% of reading |
| Stability | Within 0.1 g/L for up to 1 year without calibration, when kept clean |
| Response Time | T95 < 10 seconds |
| Measuring Method | Infrared absorbance, 850 nm |
| Calibration | Gravimetric total suspended solids analysis of a process sample (application specific); mid point 2,000 – 10,000 mg/L, high point 10,000 – 30,000 mg/L |
| Self-Cleaning | Wiper arm with PTFE blade; wiping interval set in the uPyxis app |
| Typical Wiper Life | 12 – 18 months (average 10 wipes an hour) |
| Power Supply | 22 – 26 V DC, 6 W (supply rated for 250 mA) |
| Outputs | Isolated 4–20 mA (passive, not loop powered) and isolated RS-485 Modbus RTU |
| Operating Temperature | 0 – 50 °C (32 – 122 °F) |
| Storage Temperature | −7 – 60 °C (20 – 140 °F) |
| Maximum Operating Pressure | 3.1 bar (45 psi) |
| Installation | Submersed: fixed on ¾" MNPT conduit (MA-120-B bracket), or hung by lifting ring on chain or cable |
| Minimum Clearance (submersed) | 15 cm from vessel bottom; 10 cm from vessel walls |
| Materials | 316L stainless steel body and wiper arm; PTFE wiper blade |
| Protection | IP68 |
| Dimensions (L × W × H) | 288 × 57 × 57 mm |
| Weight | 1,530 g (3.3 lb) |
| Cable | 10 m (33 ft) cable with IP67 8-pin connector, plus 1.5 m (4.9 ft) flying lead with IP67 8-pin connector |
| Supplied With | MA-1.5CR flying lead, MA-CR Bluetooth® adapter, MA-NEB USB adapter |
| Approvals | CE, RoHS |
| Warranty | 13 months (Pyxis standard warranty) |
Ideal for Wastewater Treatment
In activated sludge plants the LT-635 tracks suspended solids in aerobic and anoxic basins and in digesters, helping the plant run efficiently and stay within its environmental limits. Hung from its lifting ring on a marked chain, it can also find the sludge bed in a clarifier or thickener: lower it slowly until the reading jumps, note the depth, and the sludge blanket level follows from the tank depth.
Key Features
- Suspended solids 0–30 g/L (0–30,000 mg/L), resolution 0.1 g/L
- 850 nm infrared absorbance measurement
- Calibrated to your own gravimetric TSS results
- Automatic wiper clears bubbles, slime and sludge from the optics
- Wiping interval set in the uPyxis® app; blade typically lasts 12–18 months
- Response T95 under 10 seconds
- Built-in transmitter: isolated 4–20 mA and RS-485 Modbus RTU
- Bluetooth® or USB set-up, calibration and diagnostics with the MA-CR adapter
- 316L stainless steel body, IP68, 24 V DC at 6 W
- Fixed on conduit with the MA-120-B bracket, or hung on a chain for sludge bed profiling
