The heart of a pH measuring loop is the electrode system.Yokogawa has designed a wide range of electrodes to ensure,this heart keeps beating under the most severe conditions. Dome shape membrane in combination with L-glass ensures mechanical strength and chemical resistance. Recommended in higher temperature applications (continuously > 70ºC). • Suitable in hot caustic applications. • Suitable in processes with traces of HF. • pH, temperature range: 0 to 14 pH, 25 to 130ºC. • Glass resistance (25ºC): 600 to 900 MΩ. • High quality Ag/AgCl pin reference system. Note: The resistance may not exceed 1000 MΩunder measuring and calibrating conditions (according DIN the resistance of the glass may not exceed 1GΩ). As a general rule, the glass-resistance will increase by with every temperature decrease of 10ºC (likewise, the glass impedance will decrease bij 50% with every temperature increase of 10ºC). 普通型:SM21-AG2、SM21-AG4、SM21-AG6、SM21-AL2、SM21-AL4、SM21-AL6 高温型、耐化学腐蚀:SM21D-AG2、SM21D-AG4、SM21D-AG6、SM21D-AL2、SM21D-AL4、SM21D-AL6