User manual EUTECH INSTRUMENTS CYBERSCAN PH 5000 PH METER

[. . . ] Instruction Manual CyberScan pH 5500/ 5000 Bench pH & Ion Meter/ Bench pH Meter Technology Made Easy . . . 68X292328 Rev. 1 07/03 PREFACE Thank you for selecting the Eutech Instruments this CyberScan Series 5000 bench meter. This meter measures pH, mV and ion (Ion measurement available in CyberScan pH5500 only). The instruction manual serves to explain the use of the CyberScan Series 5000 bench meters as a step-by-step operational guide to help you familiarize with the meter's features and functions. [. . . ] When the small volume of hot sample is added to the larger volume, the temperature impact becomes negligible. 84 Instruction Manual CyberScan pH5500/ 5000 Analate Subtraction The analate subtraction method is particularly useful in the event that there is no ion specific electrode available to directly measure the concentration of the ion of interest. This method employs the addition of a sample of the ion of interest to a standard containing a different ion of known concentration. The ion of interest will quantitatively react with the ion in the standard, creating a complex and removing the ion from the standard solution. The ion specific electrode is specific for the ion in the standard solution and not for the ion of interest. The difference in mV potential is used to calculate the concentration of the ion of interest based upon this quantitative reaction. 8. 3 Select Measurement Units This screen allows you to select the units in which the meter will report the concentration of the ion of interest. The current units are displayed on the screen. Access the Select Measurement Units screen from the Ion Setup screen. The current units are displayed on the screen. Use the arrow keys to highlight the desired units. Touch enter to accept these units and return to the Ion Setup screen. OR Touch exit to return to the ion setup screen, without making any changes Select Ion Measurement Units Current UNITS ppm mg/ml mg/L mole/L Percent enter mg/ml 85 Instruction Manual CyberScan pH5500/ 5000 To Select Auto Read Mode You can use this meter when the Auto Read Mode function is active or when it is inactive. When the Auto Read function is active, the meter will lock onto a reading when the meter recognizes it as stable. The meter will not deviate from this reading until meas is touched. If the auto Read function is inactive, then the meter will continuously monitor the concentration of the ion of interest. The display on the measure screen display will indicate any fluctuation in the ion concentration. The Ion sample ID# is set the same way as previously described in pH Setup. See page 41 for instructions. To Set Ion Stability Criteria The setup screen allows you to determine how quickly the meter will respond to electrode drift. The Ion Stability Criteria is set the same way as previously described in pH Setup. See page 51 for instructions. To Set Default Temperature Ion concentration is a temperature dependent measurement. The default temperature option allows you to select the temperature that will be used by the meter to calculate the correct ion concentration. The factory default setting is 25°C. You should enter the temperature value of that solution as the default temperature in order to get the correct concentration value. [. . . ] If a silver standard is added to the sample, AgCl precipitates, effectively removing or subtracting chloride ion from the sample. Equations for known addition and known subtraction calculations are as follow: Known Addition Cs = Cstd Vstd (Vs+Vstd)10 E/S - V5 Known Subtraction Cs = Cstd Vstd Vs- (Vs + Vstd)10 E/S Cs is the concentration of the sample; Cstd is the concentration of the standard; Vs is the sample volume; Vstd is the standard volume; E is the difference in millivolt readings from the electrode; and S is the slope of the electrode determined in a previous standardization. Whereas the direct method is suitable for samples with fairly uncomplicated ionic matrices, the addition methods are advantageous with samples that have complex matrices, samples in which no ISA is added, samples in which excess complexing species are present, and samples whose concentration is in the non-linear region on the electrode response curve. 135 Instruction Manual CyberScan pH5500/ 5000 Analate Addition and Analate Subtraction In the Analate methods, the initial millivolt reading is taken with the electrode immersed in the standard; then an aliquot of sample is added, and the final millivolt reading is taken. Sample concentration is calculated from the change in the millivolt readings. [. . . ]