Hach Sigma 950, Инструкция по эксплуатации инструмента

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Optional Device Installation
7. Select another channel to configure or press
RETURN
to back up one step. Press the
MAIN MENU
function key to return to the Main Menu.
7.4.3 Dissolved Oxygen Probe Temperature Programming
1. From the Main Menu, select
OPTIONS>ADVANCED OPTIONS>DATALOG
2. Highlight Select Inputs using the
UP
and
DOWN
soft keys, then
press
SELECT
.
3. Highlight D.O. Temp. using the
UP
and
DOWN
soft keys, then press
SELECT
.
4. Press
CHANGE CHOICE
to cycle between Logged and Not Logged, then press
ACCEPT
.
5. Enter a logging interval using the numeric keypad, then press
ACCEPT
. Valid logging
intervals are shown on the status bar along the bottom edge of the display.
6. Press
CHANGE CHOICE
to select the temperature units (°C, °F).
Press
ACCEPT
.
7.4.4 Dissolved Oxygen Probe Calibration
Note: The membrane of a charged sensor must be kept moist. If the membrane is allowed to dry
completely, the electrolyte film between the membrane and the platinum will evaporate, destabilizing
the sensor. If the sensor will be out of water for more than 30 minutes, put a small amount of water in
the silicon soaking cap, and install it over the protective guard. Lift the edge of the cap to break the
seal as it is being removed. This will prevent a vacuum from forming inside the soaking cap while it
is being removed which can result in the membrane becoming stretched.
1. Connect a suitable power supply to the flow meter.
2. Power up the unit by pressing the
ON
button.
3. From the Main Menu, select
OPTIONS > ADVANCED OPTIONS > CALIBRATION > DO.
4. Enter the ambient air temperature (the current reading is displayed for reference)
using the numeric keypad.
5. Enter the elevation above sea level for the specific location.
6. Enter the membrane thickness. The operation of the 950 Flow Meter will be affected
by the choice of membrane thickness for the oxygen sensor.
7. For general purpose applications, the 1-Mil membrane is standard. This membrane
allows measurements in the 0 to 20 ppm range of dissolved oxygen and provides the
best general purpose trade-off between response time and durability.
8. The 2-Mil membrane can be used to measure up to 40 ppm of dissolved oxygen. Its
increased thickness slows the response time of the sensor, but this membrane has
increased resistance to cuts and tears. For this reason, it is recommended for use in
wastewater aeration basins where solids in the water are in rapid motion.
9. Enter the chlorinity (salinity) of the flow stream (typical wastewater is zero, sea water
is higher).
10. Place the D.O. probe in open air and press any key. The 950 Flow Meter will wait for
the reading to stabilize before storing the calibration value. The screen will
automatically return to the calibration menu.
Calibrating the D.O. Temperature
1. Place the probe and the thermometer in a liquid.
2. Wait for the temperature reading to stabilize, approximately 30 minutes.
3. Enter the actual temperature of the liquid.