Obsolete pH/Redox Electrodes
Unlike the rapid advances made in electronics the advance made in pH electrode technology have been more leisurely so any of our new electrodes will usually work with our original instruments. The biggest changes have been in the mountings and change from the P90S refillable electrodes to the newer PS90S sealed electrodes introduced in 1999. At this time the old calomel reference which contained mercury was discontinued. The original refillable electrode system had a 5/8” BSP thread which was changed to prevent the new sealed electrodes being fitted to the refillable dip tubes and being filled with the liquid salt bridge solution.
The original electrode holders made by many of the international instrument companies with separate glass reference and auto temp comps have now been replaced with sealed combination electrode which often outperform the originals and are very much simpler to maintain.
Look out for our new PS100S dip electrode with built in temp comp all manufactured in Kynar (PVDF) and the tuff tip version PTT100S also in Kynar or PVC.
Model P90S/R90S
Model P90S/R90S pH/redox electrode system for submersion into open tanks, pits or sumps. Original systems were filled with 3.8 molar KCL solution and had a sight glass at the top. The electrode mounted via a 5/8” BSP thread now obsolete as the electrode contained mercury. Manufacture ceased in 1999.
Replaced with PS90S pH sealed or RS90S Redox sealed electrode which has a larger thread to prevent fitting the new electrode to the flooded holder. Electrode is identical in size to the original, please advise the length required.
Model PES2 - PES4 or PES7
Model PES2 - PES4 or PES7 electrode system for submersion into open tanks, pits or sumps. Manufactured from PVC or Kynar and Polypropylene some had a stainless steel riser tube fitted with LB J-Box on the electrode top. (Commonly called the walking stick electrode). Manufactured from 1984, many still in use.
Replacement pH electrode in Kynar (PVDF) PN 3637-10B Replacement mV electrode in Kynar (PVDF) PN 3698-10B
Complete systems can be replaced with the PS100S for pH or the PRS100S for Redox, note the flange and riser tube are a larger diameter.