Litmus Paper, Universal Indicator Test Kit, and pH Meter

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The most easily measured pH is in liquid form. The pH of a solution depends on the degree of ionisation of an acid or alkali as well as how concentrated or dilute it is. The pH level range is from 1 to 14. The pH of 1 is the most acidic, pH 7 is pH neutral, and a pH of 14 is the most alkaline. pH also affects the taste, pH of 1 to 6 have a sour taste, the higher the levels of pH, the more acidic is in it. pH 7 has a neutral taste. pH 8 to 14, has a bitter taste.

The liquids that have pH 1-2 or pH 13-14 is corrosive that can damage or blistered skin, clothing, or other organic materials. pH 1-2 is owned by the acid solution saturated or concentrated acids, while the pH is 13-14 owned if an alkaline solution saturated or base slab. And pH 7 is owned by water or distilled water. Therefore distilled water is often used as a solvent in a wide variety of needs in the lab. And also a pure liquid is distilled water does not contain minerals, salts, or other materials.

To measure pH, tools that can be used is a litmus paper, universal indicator test kit, and a pH meter. Litmus paper is the simplest pH measuring device and can only show acidic or alkaline. Litmus paper have 2 typed, there are blue and red. Litmus paper sheets shaped like a small book 2 cm x 5 cm. Litmus paper can be cut with scissors as needed.

How to use Litmus to measure acidic solution is take the blue litmus paper with your fingers or tweezers clamp. Then enter into the solution, and lift. Do not be too long dip litmus paper, only 1 or 2 seconds will suffice. Then dry with fanned the edges with your fingers or tweezers clamp. If the litmus paper turns red it means the solution is acidic. But if the pH indicator paper remains blue it means neutral or alkaline solution.

How to use litmus paper to measure the alkalinity solution is take the red litmus paper with your fingers or tweezers clamps. Then enter into the solution, and lift. Do not be too long dip litmus paper, only 1 or 2 seconds will suffice. Then dry with fanned the edges with your fingers or tweezers clamps. If the pH indicator paper turns blue it means alkaline solution. But if the litmus paper remains red then it means a neutral or acid solution.

Universal indicator test kit to measure pH more accurately than the litmus paper. This universal indicator paper shaped sheet of paper and thicker than litmus paper, 0.5 cm x 5 cm, and have 4 different colors. This color is the main component of indicator universal consisting of materials (from top to bottom) of thymol blue, methyl red, bromothymol blue and phenolphthalein. The fourth material will change color  if given acid or base on it. The universal indicator paper has a standard color as a benchmark in determining the pH measurement. The pH standard back panel of the packaging universal indicator. pH standard consists of four color combinations of pH 1 to pH 14. Any pH level has a different color combination.

The universal indicator paper can be cut with scissors as needed, but each piece must contain all the colors that can be read and compared with a standard color. How to use universal indicator paper pH is take the paper with your fingers or tweezers on the top of the white paper or part no color combinations. Then enter into the solution, and lift. Do not be too long dip universal indicator paper, only two or three seconds is enough. Then dry with fanned the edges with your fingers or tweezers clamps. If it is dry, compare with a standard color that is behind the packaging. To determine the pH, match the color combination universal indicator as the pH standard.

Another tool is very accurate in measuring the pH, that is the pH meter. pH meter uses electricity as its energy source and has a screen that can display the measured pH. Measuring pH with a pH meter could be up to 2 digits behind the comma, for example 4.68. pH meter has a measuring device which is pH electrode that is shaped like a test tube, with liquids in it. Around these electrodes there is a protective glass so the solution is more stable and faster pH measuring.

If this tool is not used, to maintain the electrodes with the situation is the electrode dipped into the liquid. The button was in the pH meter is on and off button, to turn on and turn off the pH meter. And the calibration button, used during calibration of the pH meter. PH meter calibration is made to maintain the accuracy of the measurement of pH. Calibration is performed periodically, for example, once a month. At the time of the calibration standard pH buffer solution used is pH 4, 7, and 10. The pH measurement first do with a pH of 7 because it is pH neutral, then with pH 4 and pH 10 or vice versa pH 10 and pH 4.

How to use pH meter is press the button on to turn on the pH meter. Then grab the electrode from the handle with one hand. The tip electrode is rinsed with distilled water and wipe with a soft tissue. Do not use tissue roughened, electrode surface can be scratched and reduce the accuracy of pH readings. Then reattach to the handle, dip the electrode in the solution to be measured. Dip up to 1 cm from the bottom of the solution. Wait until the pH scale on the screen does not move anymore or stable. Write down the measured pH. Then grab the electrode and rinse with distilled water and then wipe using a soft tissue. Return the electrode by its handle and insert to the electrode fluid. Turn off the pH meter by pressing the off button.

That is part of the lab tools that can be used to measure pH from the most inaccurate until the tool most accurate pH measurement.