Innovative Buffers for Accurate Readings in Your Laboratory or Fieldwork

Press the "MODE/CAL" button to set the ORP mode; the word "mV" will be displayed in the upper right corner of the screen. Press and hold the "CAL" button for 5 seconds. When the value starts to flash, press the "MODE/CAL" button (if the flashing value is greater than 222mV) or the "HOLD/TEMP" button (if the flashing value is less than 222mV).

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