Micro IrO2-pH electrodes were prepared under three heat treatment conditions: 700 ℃ furnace cooling,870 ℃ air cooling and 870 ℃ furnace cooling.Their linear response range and response time were compared.The results indicate that heat treatment conditions have significant effect on the uniformity of iridium oxide films and the open potential stability and response time of the electrodes.After both 700 ℃ furnace cooling and 870 ℃ air cooling,the oxide films have rough surfaces,non-uniform porosities and crev...