Pulp fibers get caught in the area around the glass, clogging the electrode. Once clogged with pulp fibers the reference and glass to no longer have contact with the process, so pH measurements wander. There are two different electrode modifications to help alleviate the clogging problem. One is a flat pH glass tip (IC Controls sensor option – 6). Benefits of Flat Glass: – reduces crevices to clog, – minimizes direct impact on glass. Disadvantages of Flat Glass; surface is parallel to flow so does not contact liquid sample as well, – glass has 90º angle which can break do to thermal stress. Another proven pH sensor design incorporates a domed pH glass in a pulp modified tip (IC Controls sensor option – 73), to ensure better contact with the solution while protecting the tip from the shearing action of the stock and clogging. Benefits of Pulp Modified: – Domed pH Glass stronger in thermal stress applications, – Tip Protected from shearing of dense stock, – De watering on the electrode edge for better pH response, – Flow over surface on domed glass provides more accurate pH results.