Ijcke Schaepman reports on a a new series of non-glass pH probes which are virtually unbreakable. they also give faster, safer and more reliable measurements.
A new series of non-glass pH probes combine the latest developments in non-glass ISFET pH sensor technology with state-of-the-art sensor signal processing. They are are virtually unbreakable, fast and can be stored dry. The clog-resistant sensing area is easily cleaned using a toothbrush and requires minimal maintenance.
The new IntelliProbe series, from Sentron, bring non-glass pH probes to standard glass electrode pH meters, giving faster, safer and more reliable measurements. These high-tech ion sensitive field effect transistor (ISFET) pH probes replace fragile glass electrodes with sturdy silicon sensors.
Embedded electronics
The IntelliProbe's electronics are safely embedded in the probe and powered by a long-life replaceable battery with a 700 hour life. Intelligent signal processing converts the
ISFET and temperature signals to perfectly match the glass pH electrode signal at the measurement temperature.
This allows for accurate, fast and reliable results, while enabling full use of the glass pH meter's automatic temperature compensation facility. Includes aself diagnostics', auto shut-off, a low battery warning and easy one-button operation for calibration.
Six probe designs
IntelliProbes are available in six different probe designs and come with either a BNC or DIN connector. u The Hot-Line Series: a range of high temperature rated ISFET pH probes, designed for the use in demanding applications.
These probes incorporate a non-flow, solid state reference with a large area porous PTFE diaphragm, significantly reducing junction contamination or clogging. Using heat and chemical resistant materials and a high temperature resistant, chemically stable KCl reference gel, these probes function reliably at high temperatures up to
105oC and in contact with more aggressive chemicals.
The standard ISFET probe is not only very suitable for general pH testing, but also allows testing of very small sample volumes.
The blunt pointed ConeFET probe facilitates measurements in viscous or sticky samples. The SurFET probe makes direct measurement on flat surfaces quick and easy. u The Stream-Line series adds a probe design with flow-type reference to the family. The improved reference incorporates a large surface area diaphragm of porous PTFE and thickened KCl solution.
This ensures a constant liquid flow, preventing junction fouling and poisoning, while diffusion potential is minimised. This series incorporates a ConeFET and SurFET probe design.
Although both suitable for general pH testing, these probes are said to be extremely well adapted to both low conductive and/or pure water applications as well as highly concentrated or polluting samples. u The sharp pointed Red-Line LanceFET with handle allows easy penetration in dense, very viscous samples and even semi-solids such as meat, cheese and fruits.
The large handle ensures a good grip where the user's hands might get slippery or when used in cold environments.
The Red-Line LanceFET is meant for use in applications, where sample temperatures do not exceed 60oC.
The large surface area diaphragm of porous PTFE is significantly reducing the influence of junction contamination with fats or fibres or proteins clogging. u
ENQUIRY No 106
Ijcke Schaepman is with Sentron Europe BV, AC Roden, The Netherlands. www. sentron.nl
