User manual HANNA INSTRUMENTS HI 98186

[. . . ] Instruction Manual HI 98186 Dissolved Oxygen BOD/OUR/SOUR Meter HI 98186 Dissolved Oxygen Meter w w w. c o m 1 Dear Customer, Thank you for choosing a Hanna Instruments product. Please read this instruction manual carefully before using the instrument. This manual will provide you with the necessary information for correct use of the instrument, as well as a precise idea of its versatility. [. . . ] The hourglass icon will be shown on the display until the reading becomes stable. When the reading is stable and close to the selected standard, the CFM functional key is displayed. The meter will automatically select the 100% saturation (8. 26 mg/L) standard. The hourglass icon will be shown on the display until the reading becomes stable. When the reading is stable and close to the selected standard, the CFM functional key is displayed. The instrument will return to the main screen and will memorize the calibration data. One point manual calibration First determine the dissolved oxygen value of the sample (use a Winkler titration). Access the DO calibration screen as described in the previous DO calibration procedures. 29 Press the Manual functional key. The standard value can be changed using the ARROW keys in the range 0 to 100% saturation or 0 to 8. 26 mg/L, depending on the currently selected measuring unit. Set the standard value to the determined DO value. The hourglass icon will be shown on the display until the reading becomes stable. When the reading is stable and close to the selected buffer, the CFM functional key is displayed. Press CFM to confirm the calibration point. The instrument will return to the main screen and will memorize the calibration data. Notes: : · If the manual pressure feature is enabled, during the DO calibration it is possible to switch between changing the standard value or the pressure value by pressing the Pressure/Standard functional key or the MODE key. · If a previous calibration has been performed it is possible to erase the calibration by pressing the Clear functional key while in the DO calibration screen. 30 The "Calibration cleared" message will be displayed for a few seconds and the meter will return to the main screen. If the manual pressure feature is enabled, the Clear key will be active only for 5 seconds after accessing the DO calibration screen, and afterwards it will be replaced by the Pressure/Standard functional key. · If the DO value measured by the instrument is not close to the selected standard, the "Wrong standard" error message will be shown on the display and the calibration can't be confirmed. · While in manual calibration mode it is possible to return to the automatic calibration mode by pressing the AUTO functional key. The meter will select the standard that is closest to the current DO reading. 31 GOOD LABORATORY PRACTICE (GLP) GLP is a set of functions that allows storage and retrieval of data regarding the maintenance and status of the electrode. All data regarding DO calibration is stored for the user to review when necessary. EXPIRED CALIBRATION The instrument is provided with a real time clock (RTC), in order to monitor the time elapsed since the last DO calibration. The real time clock is reset every time the instrument is calibrated and the "expired calibration" status is triggered when the instrument detects a calibration time out. The "CAL" "DUE" tags will start blinking to warn the user that the instrument should be recalibrated. The calibration time out can be set (see SETUP for details, page 33) from 1 to 7 days or can be disabled. For example, if a 4 days time out has been selected, the instrument will issue the alarm exactly 4 days after the last calibration. [. . . ] Rinse the new membrane cap, supplied with the meter with electrolyte solution while shaking it gently. Gently tap the sides of the membrane cap with your finger tip to ensure that no air bubbles remain trapped. Do not tap directly the bottom with your finger, as this will damage the membrane. Make sure that the rubber O-ring sits properly inside the membrane cap. With the sensor facing down, slowly screw the membrane cap clockwise. [. . . ]