Can Stablcal® be used instead of Gelex to to perform verification?
Turbidimeter verification with Stablcal® or Gelex standards
Gelex standards, developed well before Stablcal® standards became available, were designed to provide a convenient way to check the calibration of turbidimeters on a daily or weekly basis. At that time, the only other way to check turbidimeter calibration was to prepare formazin standards from dilutions of a 4000 NTU standard. Now that stabilized formazin standards are available as Stablcal® in sealed ampules, they also eliminate the need for dilution and can also be used for checking the calibration of a turbidimeter on a daily or weekly basis. Stablcal® standards must first be inverted before use according to directions, however, to ensure that the formazin polymer is suspended in solution.