Independent confirmation of the outstanding performance of Metrohm's EtOH-Trode for pH measurement in fuel ethanol: in an evaluation of different combined glass electrodes by means of an interlaboratory comparison, the Metrohm EtOH electrode with ground-joint diaphragm excelled by its outstanding precision. While all the electrodes with aqueous KCl filling solution and single liquid junction presented equivalent results, only the Metrohm electrode with its double liquid junction and one other electrode presented acceptable repeatability limit values.

The comparative evaluation was conducted by Mary Ane Gonçalves et. al. and published in Sensors and Actuators B 158 (2011), p. 327-332.  The evaluation refers to the Metrohm EtOH-Trode as «electrode C» and states: «Furthermore, only the C electrode showed reproducibility limits as low as reported in the US Standard [ASTM D 6423]. Due to its remarkable precision, the C electrode presented a good compromise between trueness and precision, since its pH results were only slightly higher than the results obtained with the A, B and D electrodes. This makes the C electrode a very good candidate for pH measurements of fuel ethanol.»

Because the pH_e determination according to ASTM D 6423 and EN 15490 is time-controlled, it is essential that the sensor has a rapid response time. The Metrohm EtOH-Trode with a special membrane glass and the very precise fixed ground-joint diaphragm is particularly suitable for measuring the pH_e values of biofuel.

The comparative evaluation was conducted by Mary Ane Gonçalves et. al. and published in Sensors and Actuators B 158 (2011), p. 327-332.  The evaluation refers to the Metrohm EtOH-Trode as «electrode C» and states: «Furthermore, only the C electrode showed reproducibility limits as low as reported in the US Standard [ASTM D 6423]. Due to its remarkable precision, the C electrode presented a good compromise between trueness and precision, since its pH results were only slightly higher than the results obtained with the A, B and D electrodes. This makes the C electrode a very good candidate for pH measurements of fuel ethanol.»

Because the pH_e determination according to ASTM D 6423 and EN 15490 is time-controlled, it is essential that the sensor has a rapid response time. The Metrohm EtOH-Trode with a special membrane glass and the very precise fixed ground-joint diaphragm is particularly suitable for measuring the pH_e values of biofuel.