Piezoresistive Pressure Transmitters

With I2C interface for areas at risk of explosion

  • Piezoresistive Pressure Transmitters
    Piezoresistive Pressure Transmitters

The Keller D-line is characterized by a unique compound: the highly robust industrial pressure transducers is combined with the I2C interface. This series has been enhanced and now comes with an intrinsecally safe version. The new D Ei series is approved for gas group II applications and can be used to measure absolute and relative pressures in zone 0.


Various possible combinations for all manner of different applications

With its modular structure, the series permits numerous combinations, making it the ideal component for customisations using an I2C interface:

  • OEM pressure transmitters for fitting directly into a system’s
  • existing drilled holes: 4 LD Ei...9 LD Ei
  • OEM pressure transmitters with ultra-flexible pressure connection for screwing into existing pressure systems: 20 D Ei
  • Pressure transmitters with a pressure connection and cable gland: 21 D Ei, 23 D Ei
  • Level sensor for measuring the contents of a tank up to a maximum fill level of 3 m: 26 D Ei

The OEM pressure transmitters are available in various sizes and form the basis for the other models with ultra-flexible pressure connections or level sensors for measuring the contents
of a tank up to 3 m. The 21 D Ei and 23 D Ei models are pressure transmitters with metal casings and cable outlets. Each offers a different level of accuracy, dimensions, potential applications and numbers of variants. For example, the slightly cheaper 21 D Ei model has a simple cable gland to relieve strain and is suited to use in dry environments, while the 23 D Ei has a premium-quality cable gland boasting protection level IP 68, allowing it to be used underwater and making it ideally suited to use in flooded areas.


The I2C interface


Pressure transmitters with an I2C interface are normally only available in plastic or ceramic “consumer” housings, with only the compensatory
parameters being stored in a memory. The intrinsically safe OEM transmitters from Keller, however, have their own built-in DSP (digital signal processing) core, which balances and standardises the output values. The I2C (inter-integrated circuit) interface is designed to connect elements directly on a circuit board. The I2C is a bus system in that it connects multiple transmitters (slaves) to the same communication line. For instance, the intrinsically safe D-line combines a pressure interface for industrial use in tougher environments with an electrical interface for OEM applications.


Robust and flexible in equal measure


The D Ei series consumes very little energy and is optimised for battery-powered applications. The total error band is just ± 0,7 %FS over a temperature range of - -10…80 °C. The hermetically sealed sensor electronics and the compact stainless-steel housing (optional Hastelloy C-276) are extremely resistant to environmental factors.
With pressure ranges of 1 to 1000 bar and an internal two-chip solution that keeps the pressure sensor separate from the signal processing,
the D Ei series is extremely flexible.