EIJKELKAMP Scuba, Руководство пользователя

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Depth calibration is nothing more than “zeroing” the sensor in air, where one assumes the depth to be zero:
1 Make sure the Scuba is not in the water.
2 Follow the Scuba control software’s calibration instructions.
Notice that the depth sensor cannot distinguish between water pressure and the air pressure over that water (i.e.
barometric pressure). After you have zeroed the sensor, any change in barometric pressure will be measured as a change
in water pressure. Fortunately, water on earth is considerably heavier than air, so the error introduced by barometric
pressure changes is small.
If that’s not good enough for you, there’s always vented depth, or stage. Vented depth uses the same transducer as does
depth, except that there’s a tiny hole in the back of the transducer. If you have a vented cable (a cable that has a tube
running through it), atmospheric pressure is sensed by the transducer via the little hole. Changes in barometric pressure
will not affect the depth reading.
Vented depth cables have a desiccant-filled housing at their surface end. The desiccant keeps water from condensing in
the vent tube by letting vapor escape through a small Gortex patch. Keep that housing clean and replace the desiccants
every year or so.
4.13 Turbidity
Turbidity is measured as the fraction of an infrared light beam that is
scattered at 90° to that beam. More particles in the water mean more of
that light is scattered, so the turbidity reading is higher.
Any material that accumulates on the optical surfaces of the turbidity
sensor is indistinguishable from material in the water, so most turbidity
sensors have little wipers to clean the window(s).
Turbidity sensors require no regular maintenance, but you might check
occasionally to make sure the optical window (i.e. the little glass port on
the front of the sensor) has not been damaged by overzealous wiping.
Turbidity uses a two-point calibration; one point is zero turbidity and the
other point should be a standard approximating the turbidity of the water
you intend to monitor.
For the zero calibration:
1 Make sure the turbidity sensor is fully immersed (i.e. at least 1 ½ inches of solution over the sensor) in zero-turbidity
standard and has an unobstructed optical path.
2 Follow the Scuba control software’s calibration instructions.
For the other calibration point:
1 Rinse your sensors several times with the standard you’ll use for calibration.
2 Make sure the turbidity sensor is fully immersed (i.e. at least 1 ½ inches of solution over the sensor) in the standard
and has an unobstructed optical path.
3
Follow the Scuba control software’s calibration instructions.
A clean wiper means better measurements. If the wiper pad has deteriorated or is clogged with debris from your water
(algae, silt, etc.), you should change it. For best results, you might consider changing the wiper pad prior to each long-
term deployment.