The built-in microchip stores sensor type, serial number and calibration information including date, time, offset, slope, probe condition and buffers used. This information is automatically retrieved by edge® once the electrode is plugged in. The ability to transfer information allows for hot swapping of probes without having to recalibrate. All pH measurements are performed within the electrode and transferred digitally to the meter. This overcomes any noise issues associated with the traditional high impedance analog measuring system. Electrical noise can be generated from a built in temperature sensor and while working in a humid environment.
Conical Glass Tip
The conical shaped tip design allows for penetration into solids, semi solids, and emulsions for the direct measurement of pH in food products including meat, cheese, yogurt, and milk. The glass tip uses a special LT (low temperature) glass formulation with a lower resistance of approximately 50 megaohms compared to GP (general purpose) glass with a resistance of about 100 megaohms. This is beneficial since many food products are stored at low temperatures. As the temperature of the glass decreases in the sample, the resistance of the LT glass will approach that of GP glass. If using GP glass, the resistance would increase above the optimum range, resulting in increased impedance and ultimately affecting the measurement.
Open Junction Reference
Suspended solids and proteins found in food products will clog a conventional ceramic reference junction. This clogging will impede the measurement circuit between the indicating glass electrode and the internal reference resulting in slower response time, erratic readings and frequent electrode replacement. The open junction design consists of a solid gel interface (viscolene) between the sample and internal Ag/AgCl reference. This interface not only prevents silver from entering the sample, but also makes it impermeable to clogging, resulting in a fast response and stable readings.
Polyvinylidene fluoride (PVDF) is a food grade plastic that is resistant to most chemicals and solvents, including sodium hypochlorite. It has high abrasion resistance, mechanical strength and resistance to ultraviolet and nuclear radiation. PVDF is also resistant to fungal growth.