- June 27, 2025
Submersible Level Transmitters in Sewage and Corrosive Environments: Challenges and Requirements
A submersible level transmitter is a pressure-based sensor designed to be placed at the bottom of a tank or liquid column. It measures hydrostatic pressure, which directly correlates with the height of the liquid above the sensor. This pressure is then converted into an electrical signal (e.g., 4–20 mA or voltage output) that represents the liquid level.
Monitoring liquid levels in sewage, wastewater, or corrosive fluid tanks presents unique challenges. Level transmitter has to be designed specifically to be immersed in the corrosive environment and withstand the challenges like harsh chemicals, sludge buildup and varying pressures.
Challenges in Sewage and Corrosive Environments
Submersible level transmitters in these environments must endure:
- Aggressive chemicals (acids, alkalis, solvents)
- High humidity and condensation
- Solid or fibrous materials that may clog or damage exposed surfaces
- Biofilm and microbial buildup
- Abrasion from sediment or sludge
Without proper sensor design, accuracy and reliability can degrade quickly.
Requirements of Submersible Level Transmitters for Harsh Environments
- Corrosion-Resistant Materials
Transmitters must be constructed from chemically resistant materials such as:
- 316L stainless steel for general use
- Hastelloy, PVDF, or Teflon coatings for high chemical resistance
- Ceramic or titanium diaphragms for aggressive media
- IP68 Environmental Protection
A true submersible transmitter must meet IP68 rating, ensuring long-term submersion without water ingress.
- Non-Clogging Sensor Design
Flat or flush diaphragms prevent buildup of sludge, solids, and debris. Some models feature anti-fouling tips or protective shields to extend lifespan in dirty fluids.
- Vented Cable with Moisture Barrier
The sensor cable includes a vent tube to compensate for atmospheric pressure changes, and a moisture barrier to prevent condensation from damaging internal electronics.
- High Accuracy and Long-Term Stability
Even in turbulent or contaminated environments, quality sensors offer:
- Accuracy of ±0.1–0.5% full scale
- Minimal drift over time
- Temperature compensation for consistent performance
- Customisable Pressure Ranges
Pressure ranges can be calibrated based on tank depth or liquid density (e.g., fresh water vs. sludge), ensuring optimal sensitivity and response.
In aggressive and unpredictable environments like sewage systems and chemical storage, reliable level measurement is non-negotiable. Submersible level transmitters, built with the right materials and protective features, provide a long-lasting, low-maintenance solution for accurate liquid level monitoring.
Whether you’re upgrading an existing system or specifying for a new project, choosing the right submersible level sensor is key to ensuring operational uptime and safety.
At MeasureX, we offer a wide range of high-quality level sensors, including:
- MRL23 features a PVDF housing and ceramic diaphragm, making it perfect for corrosive and sewage environments with chemicals like hydrochloric or nitric acid, while maintaining high precision and IP68 protection.
- MRL21 is a compact submersible level transmitter with a rugged SS316L or Tantalum diaphragm, ideal for clean or mildly aggressive liquids in confined spaces. It offers high accuracy (up to 0.1% FS) and reliable performance in long-term submerged applications.
- MRL24 is a submersible level transmitter with an integrated temperature sensor, enabling simultaneous monitoring of liquid level and temperature. Built with a durable SS316L or Tantalum diaphragm, it offers high accuracy and long-term stability in harsh environments. Ideal for applications requiring dual-parameter measurement with compact IP68-rated construction.
Need help selecting the right submersible transmitter for your corrosive application?
Contact MeasureX Australia for expert advice and a complete range of robust level sensors designed for harsh and corrosive environments.
