Pressure sensor, diameter from 9 to 19mm — Series 3L-10L

Description

Series 3L...10L – a new line of sensors that come in various designs: small sizes, different membrane shapes, etc. Keller has developed a new laser welding technology that allows welding a very thin membrane to the housing. All presented designs still meet the high level of stability and quality for which Keller has become known worldwide.

Each sensor is supplied with a calibration certificate indicating sensitivity, linearity, zero, temperature error, and compensation resistor parameters, which mainly account for zero drift and temperature zero.

The sensor design allows for a non-welded connection later using an O-ring seal. This protects the membrane from possible stresses and guarantees pressure and temperature readings obtained during calibration. Each sensor contains a piezoresistive silicon chip mounted on a polished metal surface. This assembly is then welded to the housing and filled with silicone oil. A thin membrane is laser welded on top, making the structure hermetic. The medium pressure acts on the membrane made of stainless steel and is then transmitted through the oil to the silicon measuring chip.

The use of laser welding technology allows sensor diameters starting from 9.5 mm. However, there is some dependence between diameter and allowable measurement pressure: the lower the pressure level, the larger the membrane diameter required. This is due to the thermal expansion of the oil, which causes additional pressure on the silicon chip. The smaller the diameter and the lower the measurement pressure, the greater the influence of the resulting internal pressure and, accordingly, the measurement error.

Sensors for high pressures are thicker because higher pressures require thicker substrates for silicon chips to ensure reliability.

Options

• Membrane/housing: Hastelloy C-276, Titanium
• Seals for aggressive media: EPDM, Karlez
• Versions with threaded fittings
• Oil for low temperatures down to -55°C
• Fluorinated oil for oxygen applications
• Olive oil for food applications
• Built-in Pt1000 temperature sensor
• Special characteristics: Linearity, overload pressure, low temperature coefficients
• Special tests
• Built-in compensation PCB (see Series LX, LY)
• Mathematical model and calibration matrices