Installation of portable acid meter (Pen PH meter)

   Portable acidity meter （Pen PH meter ) is a common instrument and equipment, mainly used for precision measurement of liquid medium acidity value, with the corresponding ion selective electrode can also measure the ion electrode potential MV value, so the PH meter is widely used in industry, agriculture, scientific research, environmental protection and other fields.


    Installation of the PH meter:

　　①The voltage and frequency of the power supply must be in accordance with the data specified on the instrument nameplate, and must be well grounded, otherwise the pointer may be unstable during the measurement.
　　②The instrument is equipped with glass electrode and glycol electrode. Clip the rubber wood cap of the glass electrode on the small clip of the electrode clip. Clamp the metal cap of the glycolic electrode on the large clamp of the electrode clamp. The height of the two electrodes can be adjusted with the pivot screw on the electrode clamp.
　　③The glass electrode must be soaked in distilled water for more than 24 hours before first use. It should also be soaked in distilled water when it is not used normally.
　　④The glycerol electrode should be soaked in saturated *** solution before first use, not in distilled water with the glass electrode. When not in use, also soak in saturated *** solution or use the rubber cap to cover the lower capillary hole of the glycol electrode.

　　Secondly, the calibration of PH meter
　　①Turn the “pH-mv” switch to pH position.
　　②Turn on the power at the beginning of the light is on, preheat 30 minutes.
　　③Take a small beaker of distilled water and gently absorb the excess water droplets on the glass electrode with filter paper. Put the selected standard buffer solution of known pH into the small beaker. Immerse the electrode. Take care to keep the glass electrode pellet and the capillary pores of the mercury electrode immersed in the solution. Gently shake the beaker to make the solution in contact with the electrode uniform.
　　④Turn the range switch to 0~7 or 7~14 according to the pH of the standard buffer solution.
　　⑤Adjust the temperature control knob so that the temperature indicated by the knob is the same as the room temperature.
　　⑥Adjust the zero point so that the pointer points at pH7.
　　⑦Gently press or slightly turn the reading switch to make the switch stuck. Adjust the positioning knob so that the pointer points exactly at the pH value of the standard buffer. Release the reading switch and repeat the operation until the value is stable.
　　After calibration, do not turn the positioning knob again, otherwise it needs to be re-calibrated. Remove the small beaker of standard solution and rinse the electrode with distilled water.

　　Finally, the measurement with PH meter
　　① Absorb the excess water droplets on the electrode or rinse it twice with the measured solution, then immerse the electrode into the measured solution and gently turn or shake the small beaker to make the solution contact the electrode evenly.
　　②The temperature of the measured solution should be the same as the temperature of the standard buffer solution.
　　③Calibrate the zero position, press the reading switch, the value pointed by the pointer is the pH of the solution to be measured. if the pointer reading exceeds the scale when measuring within the range of pH0~7, the range switch should be placed at pH7~14 before measuring.
　　④After measurement, let go the reading switch, the pointer must point at pH7, otherwise readjust.
　　⑤ Turn off the power, rinse the electrode and soak it according to the previous method.