Hach ORBISPHERE 3650 ATEX Manuel D'utilisation De Base page 13

Sensor calibration - see
Start automatic data acquisition - see
Start memory storage view - see
Display program identification information
6.2 Taking measurements
Once the system is calibrated, you should be able to begin taking measurements. Connect the top-
mounted inlet to accept your sample, typically this is accomplished by connection to a sampling
valve. The sample flow can be regulated by adjusting the knurled stainless steel knob on top of the
flow chamber.
Minimum flow rates, measurement limits and response times for the various available membranes
are given in the accompanying Sensor Manual.
To switch between gas measurement and temperature measurement, press the Up/Down Arrow
buttons.
To backlight the LCD for approximately three minutes, press the Backlight button.
Note: For measurements of gaseous samples in % units, you must open the barometric pressure sensor relief
valve switch on the top of the instrument from time to time, to allow the pressure inside the instrument to equilibrate
to the barometric pressure.
6.3 Preconditioning sensors
You can expect a more rapid and accurate first result if you precondition the sensor before you take
readings. You may want to precondition prior to each series of measurements, depending on
frequency of use.
To precondition, connect the flow chamber to a convenient sampling source at or below expected O
levels. If measurements take place in carbonated samples, precondition with carbonated water.
Open the sampling valve on the flow chamber, just enough for a trickle. Then, switch on the
instrument and watch the LCD. You will see the values drop.
If you are measuring in the 0.1 ppm range, then only a short time is required for the display to fall to
this level, whereas ppb level measurements may require the sensor to remain exposed to the sample
for half an hour or more. You will establish your own requirement with experience.
Once the LCD displays the expected level of O
preconditioned and ready to use.
6.4 Storing measurements in the instrument
The instrument will store up to 500 gas measurement values, labeled by numbers 0 through 499,
along with the current date and time of each measurement. You have the choice of acquiring this
information manually or automatically, as described below.
Before storing measurements, you should verify the date and time settings of the instrument's
internal clock, as described in
Sensor calibration on page 20
Automatic data acquisition
Viewing stored measurements
, close off the sample. The sensor is now
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Clock settings on page 22.
on page 14
on page 14
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