PH ph Ph pH

 

Introduction

pH = -log10[H+]

 

 

 

Fundamentals of pH

 

 

 

 

pH Determination

 

 

 

pH Scale

 

 

 

How Do We Measure pH?

 

 

 

How Does a pH Meter Work?

 

 

 

Measuring Tools

 

 

 

How Does a pH Meter Work?

 

 

 

Electrodes

 

 

 

pH Meters

 

 

 

Sample Collection

 

 

 

Bench pH Measuring

 

 

 

Our Procedure

  1. Calibrate lab pH meter
  2. Sample collection throughout plant/distribution system
  3. Between measurements, rinse electrodes with distilled water and then with the next sample to be measured
  4. Pour sample in beaker and immerse electrode
  5. Add magnet, turn on stir plate
  6. Record pH and temperature when meter says ready/hold
  7. When finished ensure electrode is placed in storage solution

 

 

How Do We Know Our pH Meters Are Reading Correctly?

 

 

Calibration

 

 

 

Electrode Do's and Don'ts

DO's DON'Ts
  • Do store electrode in electrode storage solution
  • Do not store electrode in distilled water
  • Do calibrate meter daily
  • Do not leave exposed to air
  • Do keep electrode moist
  • Do not wipe electrode but blot with lint free tissue

 

 

 

Replace Your Electrode

 

 

Factors Affecting pH

 

 

Inline vs Bench pH Measurement

Inline pH Analyzers Bench Top Meters
  • continuous contact with the sample
  • influenced by exposure to atmosphere so you may experience "drifting"
  • conditioned to the process stream
  • gain or loss of CO2 may result in different pH readings
  • does need calibration and maintenance
  • does need calibration and maintenance daily
  • should be checked periodically against bench top meter
 

 

*If comparing the two, +/- 0.1 is ideal but +/- 0.2 is realistic

 

 

 

pH Facts

 

 

 

Chemicals That Raise pH

 

 

Chemicals That Lower pH