Refillable Combination pH Electrode with BNC Connector

The HI1131B uses high temperature (HT) glass, spherical bulb, glass body, single ceramic frit, double junction and is refillable with 3.5M KCl. Features: – High Temperature Glass Formulation: The measurement of pH at very high temperatures is detrimental to the sensitive glass bulb and will shorten the life of it. A pH electrode with general purpose (GP) glass will have a resistance of 100 megaohms at 25 C while the resistance of HT glass is around 400 megaohms at 25oC. As the HI1131B is used at elevated temperatures the resistance decreases to approach the that of GP glass. The HI1131B is suitable to use with samples that measure from 0 to 100 C.
– Spherical Glass Tip: The spherical bulb is for general purpose use. Other tip shapes include conic for penetration and flat tip for surface measurements.
– Glass Body: The glass body is ideal for laboratory use. The glass is resistant to many harsh chemicals and is easily cleaned. The glass body also allows for a fast transfer of heat to the internal reference electrolyte. The mV generated by the reference cell is temperature dependent. The faster the electrode reaches equilibrium, the steadier the reference potential.
– Single Ceramic Double Junction Reference: The junction also known as a salt bridge is necessary component of the electrical circuit. The movement of ions must flow through the junction for a steady reading. The outer reference has a single ceramic frit. The ceramic is a porous material that is easily fused with the glass body and has a similar expansion coefficient. A single ceramic junction has a flow rate of 15-20 L/hour. Other junction types are available with higher flow rates and made with different materials.
– Refillable: The HI1131B is a refillable probe. Since it is a double junction pH electrode the fill solution is the HI7082 3.5M KCl. This solution does not contain any silver as with single junction electrode. The absence of silver will prevent any silver precipitate from forming at the junction surface and clogging it. Clogging of the junction will result in drifty and erratic readings.