Hydrostatic level measurement sensor for industrial tanks containing high concentrations of caustic cleaning agents and viscous soap mixtures. This sensor can be installed in chemical blending or detergent manufacturing facilities where media compatibility and sensor longevity are critical.
- Chemical compatibility with 50% Sodium Hydroxide (NaOH) concentrations.
- Flush-mounted diaphragm design to eliminate clogging from viscous soap residues.
- Capacitive ceramic sensing technology providing high overpressure resistance.
- Hydrostatic pressure measurement for accurate volume tracking in vertical storage tanks.
Industrial detergent manufacturing and chemical blending processes often involve the storage of highly concentrated caustic substances such as sodium hydroxide. In this specific application, a storage tank contains a mixture of soap and water with sodium hydroxide concentrations reaching up to fifty percent. The primary challenge for instrumentation in this environment is twofold: the highly corrosive nature of the alkaline solution and the physical properties of the soap, which can be viscous and prone to solidification or build-up. Standard pressure sensors with recessed diaphragms and small internal ports are susceptible to clogging in these conditions, leading to inaccurate readings and frequent maintenance requirements.
To address these challenges, a hydrostatic level measurement solution utilizing the LMK351 series was implemented. This transducer is specifically designed for small system pressures and container level monitoring. The core of this solution is a capacitive ceramic sensor element. Unlike traditional metallic diaphragms, the ceramic alumina Al2O3 construction offers exceptional chemical resistance and high overpressure capability. In environments where sodium hydroxide is present, the choice of materials for the media-exposed parts is critical for long-term stability. The use of a high-purity ceramic diaphragm ensures the sensor remains inert to the caustic effects of the alkali, preventing the pitting or degradation that often affects stainless steel components in similar concentrations.
The mechanical design of the LMK351 series features a flush-mounted diaphragm, which is essential for handling pasty or viscous media like soap. By positioning the sensing surface flush with the process connection, there are no cavities or dead spaces where soap residue can accumulate and harden. This “clog-free” design ensures that the hydrostatic head of the liquid is always accurately transmitted to the sensor, regardless of the viscosity of the fluid or the presence of suspended solids. The transducer was integrated into a remote monitoring system via a zero to ten volt output signal, allowing operators to track tank levels from a centralized digital display without needing to be in close proximity to the corrosive chemicals.
The solution utilized a parallel G one and a half inch male thread according to DIN3852. This parallel thread interface is particularly advantageous for flush sensors as it allows for a secure, repeatable seal using FKM or EPDM gaskets, ensuring that the aggressive media is contained within the process. For even more extreme chemical environments, the series offers options for PVDF process connectors, providing a modular approach to chemical compatibility. This robust instrumentation setup allows for continuous, reliable level tracking in harsh industrial blending environments where standard sensors would typically fail due to corrosion or mechanical blockage.
LMK351 Flush Ceramic Diaphragm Level Transducer
- Part Number: 471-6000-3-3-TR0-M00-1-1-C-000
- Pressure Range: 0 – 6 mH2O g
- Output Signal: 0 – 10V 3 wire
- Accuracy: 0.35% FS
- Electrical Connection: PUR cable outlet, with vent tube (IP 68)
- Cable Length: 2m of cable
- Process Connection: G 1 1/2″ male DIN3852 with flush diaphragm
- Process Connector Material: Stainless Steel
- Diaphragm Material: Ceramic Alumina Al2O3 99.9%
- Media Exposed Seals: FKM