Hanna Instruments offers a wide variety of pH electrodes that are designed for many different applications. The type of glass used for sensing pH, bulb shape, body material, type of junction, type of reference and electrolyte used are just some of the design considerations.
The FC200D uses low temperature (LT) glass, conical bulb, food grade PVDF body, and open junction with viscolene gel electrolyte.
Low Temperature Glass Formulation
The glass tip uses a special LT glass formulation with a lower resistance of approximately 50 megaohms compared to general purpose (GP) 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 increase approaching that of GP glass at ambient temperatures. If using GP glass, the resistance would increase above the optimum resistance for the high impedance input of a pH meter.The FC200B is suitable to use with samples that measure from 0 to 50°C.
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.
PVDF Body
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.
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 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.
DIN Connector
The FC200D uses a DIN connector. This type of connector is generally proprietary to the meters they are supplied with and may not be interchangeable. Other type of connectors include BNC, screw type, T-type, and 3.5mm to name a few.
