Our company was invited to an oil refinery to investigate problems associated with pH measurements of cooling water circuits, crude oil washes, and a storage pond. Residual oil was present in some samples. The electrodes in use were quality,state of the art electrodes from a number of reputable manufacturers, including “Self Cleaning“ electrodes. Measurements from on-line analysers were checked against spots tests with hand-held meters and laboratory meters. The concern was lack of consistency between measurements on the same samples, resulting in limited trust of on-line measurements. One system had been abandoned.

          While fouling of the membrane and contact zone between the refenence electrolyte and sample was the underlying problem, the variation between the laboratory and on-line measurements was caused by different frequencies of cleaning. The laboratory electrode was our model GATionode IJ44 with removable sleeve which allows easy to cleaning on a daily basis. However, the on-line installations revealed electrodes which were difficult to remove, or complex assemblies which took considerable time to disassamble. Regarded as a nuisances by plant operators, these electrodes were cleaned infrequently.

          The GATionode IJ48 was developed to address this need for consistency. The design utilised the well established principle of the GATionode IJ44, but includes a detachable cable and simple fitting to expand the application to on-line. A unique waterproof connection based on the BNC connector was developed for ease of use, reliability and low cost. The added attraction was compatible with “Stick“ pH meters with exposed BNC sockets. The GATionode IJ48 bridges the three main types of pH measurement – laboratory, hand-held and on-line. The redesign also provided an opportunity to add improvements to the IJ configuration such as the ”bullet” membrane for fast response.

          Implementation of the GATionode IJ48 in the refinery resulted in the following statement by a consultant employed by the refinery to tackle the pH problem: “For the first time we are getting agreement between on-line and lab measurements”.

_______________________________________________________________________

Material:
Temp. range:
Max. pressure:
Barrel Diameter:
Cable Length:
pH Range:
Reference:

Pack contains electrode; protected sleeve (Figure 3); penetration sleeve (Figure 4); wetting caps; syringe; instruction manual

• Inline-Adapter-Kit (P/N – IL01):
   Suits standard PVC T-pieces 20-50mm with 20mm side outlet (class 9).
   Contains: cap with hole including seal, threaded PVC adaptor and flange    seal.

• Pipe Extension Kit (P/N – PE01):
   Suits standard 20mm PVC pipe (class 12).
   Contains: 2x caps with holes, 2x threaded inserts, top seal, flange seal.

• Gel Reference Electrolyt (P/N – RE02)
   15ml dropping bottle of KCl-Gel.

• Small volume kit pack (P/N – SV01):
   Contains: 10 x tapered centrifuge tubes

• Clamp Adaptor (P/N – CA01):
   Suits electrod clamps with 16mm hole