Different shapes of a probe tip

The pH probe tip can be manufactured in different shapes, depending on the application.

The classical sphere shaped membrane offers low electrical resistance due to its large surface area giving good contact with the sample. The weakness of the sphere is that it is relatively fragile. In practice, there is a trade-off between low electrical resistance, or in other words to get the optimal connection with the sample, and its ruggedness.

Download Standards from ANSI

Common shapes of the probe tip

probe tip
  • The sphere tip is recommended for general use in aqueous or liquid solutions. The tip is fragile and requires careful handling. Mainly used in laboratories. The sphere tip provides a wide surface of contact with the sample => Low resistance.

  • The cone tip is seen as a universal design as it is robust, easy to clean and of medium resistance. Universally applicable.

  • The cylinder tip is similar to the cone tip, but slightly more robust. Medium resistance.

  • The dome tip is an alternative for in-line process pH measurements and automatic cleaning applications. Shock proof. The downside is the dome tip provide minimal contact with the sample giving a high resistance.

  • The flat tip electrode is ideal for continuous in-line monitoring, and with solutions containing aggressive chemicals. The flat sensor tip virtually eliminates deposits that can foul the electrode, significantly reducing necessary maintenance. Flat tip is also the obvious choice for direct surface measurement on skin, leather, paper, etc. As for the dome tip, the flat tip is of high resistance.

  • A spear tip is recommended for measuring pH of semi-solid material samples. Meat, sausage, cheese and soil are typical applications.

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