Product category:
pH and conductivity meters
News Release from: Russell Mainstream Supply | Subject: PH Plus
Edited by the Laboratorytalk Editorial
Team on 20 April 2005
Accurate pH measurement redefined
Highly sensitive pH and reference electrodes offer enhanced accuracy, very fast response and greater stability
Russell Mainstream Supply says that, with the development of its pH Plus technology, past problems with accurate pH measurement such as long term drift, reproducibility and temperature errors have been virtually eliminated These highly sensitive pH and reference electrodes offer enhanced accuracy, very fast response and greater stability
This article was originally published on Laboratorytalk on 15 Apr 2005 at 8.00am (UK)
Related stories
Probes measure water disinfection
Range of robust, industrial disinfection probes for measuring chlorine, chlorine dioxide, hydrogen peroxide, ozone and peracetic acid
World's first Windows CE driven bench meter
The new RMS PCD 6500 full-colour touchscreen research-grade benchtop instrument combines exact measurements and ease of use with quick data analysis and a perfect communication platform
The non silver reference system used in this range is said to ensure better performance in samples prone to contamination from silver reference systems.
Advantages include quick calibration - response time in pH buffers is described as remarkable: time taken to respond to pH change 7 to 4 buffer is under 15 seconds (standard AgCl can take over a minute).
Faster measurements - pH Plus electrodes reach equilibrium in samples significantly faster than conventional electrodes, especially when there is temperature variation: stabilisation time with a 40C shift in temperature in pH4 buffer is under 15 seconds (conventional AgCl can take up to 5 minutes).
Further reading
PH and Redox electrodes for use in swimming pools
Russell Mainstream Supply has launched a new range of pH and Redox sensors which require infrequent calibrations, typically once per month in their first year of use
Mtec 2004 preview: ABB
ABB will be presenting the latest technology from its comprehensive range of instrumentation products and systems at Mtec 2004 (Birmingham NEC, 11-12 February 2004)
Drift - long term drift on pH Plus is greatly reduced, therefore the need for frequent re-calibration is virtually eliminated (in tests over a period of 90 days the pH Plus electrode drifted by only 2mV in pH7 buffer, whereas a conventional AgCl drifted by over 6mV).
Reproducibility: the pH Plus electrode displays unsurpassed reproducibility when returned to the original sample after being exposed to extreme conditions of pH and temperature: after being immersed in pH4 buffer at 60C for four minutes the mV reading was -4mV, subsequently the probe was introduced to pH7 buffer at room temperature the mV variation was found to be -5mV (ie, within 1mV).
The same experiment was carried out using a conventional AgCl probe and gave the following results: pH4 buffer at 60C for four minutes was -2mV, placed in pH7 buffer at room temperature the mV variation was -6mV (ie, approx 4mV variation).
Linearity: pH electrodes of all types show good linearity over the pH range 2-12.
pH Plus assists the user to make reliable measurements as there is no temperature hysterisis (of memory) effect caused by variations in temperature, says Russell mainstream - results are achieved in seconds rather than minutes.
Not only is time saved by rapid equilibration but accuracy and confidence in the result allows use of pH Plus probes in a wide variety of samples without recalibration.
Fast response and excellent reproducibility will also facilitate accurate results from unskilled operators, once drift and uncertainty of response have been eliminated.
• Russell Mainstream Supply: contact details and other news
• Email this article to a colleague
• Register for the free Laboratorytalk email newsletter
• Laboratorytalk Home Page
Search the Pro-Talk network of sites
