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OBS500 Smart Turbidity Meter with ClearSensor
®
Technology
22
used and wired appropriately for the measurement device. See TABLE
settings.
TABLE 7-8. RS-232 Settings
Bits per second
9600
Data bits
8
Parity
None
Stop bits
1
Flow control
None
Measurement commands are the same for RS-232 and SDI-12 as shown in
7.5 Calibration
7.5.1 Turbidity
Field recalibration is not recommended and usually not needed until the
OBS500 is sent back to Campbell Scientific for the two year service. We
recommend checking the calibration in the field as described below. If a
9-point calibration is needed, the OBS500 should be sent to Campbell
Scientific to perform the calibration.
The normalized response of an OBS500 sensor to SDVB turbidity over the
range from 0 to 4,000 TU is shown in FIGURE
. As shown on the inset, the
response function is contained within region A, the linear region, of the
universal response curve. However, there is residual nonlinearity that is
removed by calibration and by computation of a TU value with a 2nd-order
polynomial. This section explains how to do a turbidity calibration.
Содержание OBS500
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