What is a standard solution?

      

　　What is a standard solution? A standard solution is a solution that contains a parameter of a particular concentration, such as a standard solution of Cl or Fe. When a standard solution is used instead of a sample for testing, the results obtained should match the concentration of the known standard solution. If a consistent result is obtained, the test operation is correct. If there is any significant error (greater than 10%) between the results and the standard value, it indicates that there is an error and needs to be analyzed. Hach has a variety of standard solutions with concentrations within most test ranges. Some standard solutions are so unstable that they are difficult to formulate and use that they cannot be used. Such standard solutions include hydrogen sulfide (H2S), chlorine dioxide (ClO2), dissolved oxygen (DO), and ozone (O3). The standard solution of liquid chlorine can only be formulated as a high-concentration solution, so it must be diluted with high-purity water and glassware that does not consume liquid chlorine is used.

　　Standard solutions can also be used to calibrate instruments such as colorimeters and spectrophotometers, as well as electrochemical instruments such as pH meters and pH/ISE meters. Standard solutions of different concentrations can be used to draw calibration curves, so that the resulting calibration curves can be used to check the concentration of the test sample.

　　Where can I check the standard solution? Common metal element standard solutions can be checked on the National Standard Products Network. As shown below

　　Enter the name of the standard solution you want to inquire about and click Search to see the price and concentration of the standard solution.