User manual HANNA INSTRUMENTS HI 96822

[. . . ] 7 MEASUREMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 TO CHANGE MEASUREMENT UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 TO CHANGE TEMPERATURE UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 MAKING A STANDARD SOLUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Refractive Index is an optical characteristic of a substance and the number of dissolved particles in it. Refractive Index is defined as the ratio of the speed of light in empty space to the speed of light in the substance. A result of this property is that light will "bend", or change direction, when it travels through a substance of different refractive index. When passing from a material with a higher to lower refractive index, there is a critical angle at which an incoming beam of light can no longer refract, but will instead be reflected off the interface. The critical angle can be used to easily calculate the refractive index according to the equation: sin (critical) = n2 / n1 Where n2 is the refractive index of the lower-density medium; n1 is the refractive index of the higher-density medium. In the HI 96822 refractometer, light from an LED passes through a prism in contact with the sample. An image sensor determines the critical angle at which the light is no longer refracted through the sample. Specialized algorithms then apply temperature compensation to the measurement and convert the refractive index to: PSU, PPT or S. G. PSU is defined as a definitive salinity-conductivity ratio relationship. This information is published in The Joint Panal of Oceanographic Tables and Standards. PPT (10-3) is an older used salinity scale where salinity is defined by "the salt content is the weight of the inorganic salts contained in 1 kg of seawater if all bromide and iodide are replaced by an equivalent amount of oxides" (Knudsen, 1901). 4 Specific Gravity (20/20) is based upon the published relationship between density at 20 °C and the mass of the dissolved salts in the seawater sample (CRC Handbook of Chemistry and Physics, 87th Edition). FUNCTIONAL DESCRIPTION TOP VIEW 1. BOTTOM Liquid Crystal Display (LCD) READ Key (User Measurement) ZERO Key (User Calibration) RANGE Key (User Measurement Unit) ON/OFF Stainless Steel Sample Well and Prism Secondary Display Primary Display 9. 9. Battery (blinks when low battery condition detected) Measurement in Progress Tag SETUP: Factory Calibration Tag CAL: Calibration Tag Automatic Temperature Compensation (blinks when temperature exceeds 0-40°C / 32-104°F range) Primary Display (displays measurement and error messages) Temperature Units Secondary Display (displays temperature measurements; when blinking, temperature has exceeded operation range: 0-80°C / 32-176°F) Range indicator MEASUREMENT GUIDELINES · · · · · · · Handle instrument carefully. Do not spray water to any part of instrument except the "sample well" located over the prism. This includes most organic solvents and extremely hot or cold solutions. Absorb sample on soft tissue and rinse sample well with deionized or distilled water between samples. Do not use metallic tools such as needles, spoons or tweezers as these will scratch the prism. 6 CALIBRATION PROCEDURE Calibration should be performed daily, before measurements are made, when the battery has been replaced, between a long series of measurements, or if environmental changes have occured since the last calibration. Two instrument test screens will be displayed briefly; all LCD segments followed by the percentage of remaining battery life. Using a plastic pipette, fill the sample well with distilled or deionized water. Make sure the prism is completely covered. Note: If the ZERO sample is subject to intense light such as sunlight or another strong source, cover the sample well with your hand or other shade during the calibration. [. . . ] The table below lists several Sodium Chloride solutions and there expected ppt Seawater value. 9 To make a Standard NaCl Solution (g/100 g), follow the procedure below: · Place container (such as a glass vial or dropper bottle that has a cover) on an analytical balance. · To make an X NaCl solution weigh out X grams of high purity dried Sodium Chloride (CAS #: 7647-14-5: MW 58. 44) directly into the container. · Add distilled or deionized water to the container so the total weight of the solution is 100 g. g of NaCl g of Wat er 5% NaCl 10% NaCl 15% NaCl 5. 00 10. 00 15. 00 95. 00 90. 00 85. 00 Tot al Weight 100. 00 100. 00 100. 00 Expect ed ppt Seawat er Value 48 96 145 BATTERY REPLACEMENT To replace the instrument's battery, follow these steps: · Make sure the instrument is off. · Turn instrument upside down and remove the battery cover by turning it counterclockwise. · Extract the battery from its location. [. . . ]