pH Probe FAQS
1. What's the lifetime of a pH probe?
The expected lifetime of a correctly used and maintained pH probe is around one to three years. Some factors such as high temperature and measuring at extreme pH values contribute to a reduction of the lifetime even for probes that have been well maintained and properly stored. When a meter starts performing poorly, it may be possible to regenerate the pH-sensitive glass membrane and restore the electrode to its previous level of performance.
2. How do you select the correct pH probe?
For optimal pH measurement it is crucial to choose the right pH probe for each application. The most important sample criteria are: chemical composition, homogeneity, temperature, process pressure, pH range and container size (length and width restrictions). The choice of sensor becomes of particular importance for non-aqueous, low conductivity, protein-rich and viscous samples where general purpose glass electrodes are subject to various sources of error. The response time and accuracy of an electrode is dependent on a number of factors. Measurements at extreme pH values and temperatures, or low conductivity may take longer than those of aqueous solutions at room temperature with a neutral pH value.
3. How should you maintain/clean a probe?
Regular maintenance is very important for prolonging the lifetime of any pH probe. Probes with liquid electrolyte need the electrolyte to be topped-up when the level threatens to become lower than the level of the sample solution. This maintenance prevents a reflux of the sample into the probe. The complete reference electrolyte should also be regularly changed, approximately once a month. This ensures that the electrolyte is fresh and that no crystallization occurs due to evaporation from the open filling port during measurement. It is important not to get any bubbles on the inside of the probe, especially near the junction. If this happens the measurements will be unstable. To get rid of any bubbles, gently shake the probe in a vertical motion as with a fever thermometer.
To clean the probe, rinse it with deionized water after each measurement but never wipe it with a tissue. The surface of the paper tissue can scratch and damage the pH-sensitive glass membrane, removing the gel-layer and creating an electrostatic charge on the electrode. This electrostatic charge causes the measured signal to become very unstable. Special cleaning procedures may be necessary after contamination with certain samples.
Our wide portfolio of in-line solutions covers process pH and ORP measurement for all process industries.
Every application has specific demands which is why METTLER TOLEDO has a measurement solution for every need. Whether your process is at a very high temperature, in a sterile environment or in a hazardous area we have an analog or digital pH probe that will provide accurate, dependable measurements.
Our range of in-line pH probes and meters include
- Hygienic design pH probe
- ATEX and FM approved probe
- pH probe for pure and ultrapure water
- Digital sensors with predictive diagnostics
- Non-glass pH probe
في التطبيقات التي تكون فيها القياسات الدقيقة مهمة، تقدم مجسات الحموضة والاختزال والأكسدة القابلة لإعادة الملأ دقة عالية وعمرًا طويلاً.
Sterilizable, hygienically designed pH and redox (ORP) sensors offering high measurement accuracy in pharmaceutical, biotech and food applications.
Specialized, highly durable pH and redox (ORP) probes designed to perform reliably under harsh conditions in chemical applications.
Unique pH probes designed for reliable pH measurement in low conductivty, ultrapure and pure waters.
منحل بالكهرباء قابل لإعادة الملء لعمر تشغيلي أطول لجهاز الاستشعار
القدرة على اختيار منحلات بالكهرباء محددة التطبيق
تمنع مصيدة سيلفر ايون من تسمم الكبريتيد
تشير بيانات تشخيص إدارة جهاز الاستشعار الذكي إلى الجداول الزمنية للصيانة
تتوفر في موديلات درجة الحموضة والأكسدة/والاختزال والأكسدة
Designed for regular SIP and CIP processes
For use in bioreactors with high pressures
Diagnostics help prevent batch interruptions
Unique models for upside-down installation
Liquid, gel and polymer reference electrolytes
For use in difficult industrial environments
Withstands abrasive, sticky or oxidizing media
Diagnostics help manage sensor cleaning efforts
Titanium models prevent sensors from breaking
Liquid, gel and polymer reference electrolytes
Designed for water treatment applications
Free-flowing liquid electrolyte for reliability
Eliminates need for flow bowl for high accuracy
Plug and measure technology for fast set-up
Available in pH and ORP/Redox models
ISFET pH probes offer a non-glass solution for industries such as food or biotechnology, where safety and hygienic design are paramount.
Easy-to-use, portable pH meters for industrial applications. They offer high measurement accuracy in a robust, weatherproof design.
ISM accessories such as software or transmission solution allow you to take full advantage of ISM technology.
Gamma-sterilizable sensors in single-use format for measuring pH and DO. Designed for biotech companies that manufacture single-use bags.
Unbreakable, solid-state ISFET technology
FDA and 3-A compliant materials
Hygienic design is EHEDG tested
One-handed operation and an intuitive interface
Weatherproof and robust for demanding environments
Rigorously drop tested to ensure durability
Easy data management with 2,000 stored data points
Calibrate your sensors away from the process
Monitor sensor history, diagnostics & inventory
Easy system verification with sensor simulators
Connect sensors to a computer or mobile
Suitable for use in a wide range of applications
Compatible with standard METTLER TOLEDO transmitters
Long-term measurement stability and performance
Designed for 1" Eldon James port disc