Siemens SITRANS SL, Руководство по эксплуатации, Страница: 86 / 212

Commissioning
6.2 Starting SITRANS SL for the first time
SITRANS SL
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Operating Instructions, 12/2010, A5E01132948-04
6.2 Starting SITRANS SL for the first time
6.2.1 Defining the path length
It is recommended that the open ends of the purging tubes represent the reference points
from which the path length is determined. When the flanges are permanently installed,
measure the distance between the outside of the flanges with an accuracy of at least ±10
mm (±0.4"). This distance is used to calculate the path length by subtracting the length of the
flange tubes and will later be used in the analyzer for the calculation of the gas
concentration. In the area where the purging gas and the measurement gas are mixed there
will be a zone of uncertainty. This zone will depend on the purging flow and the flow of the
measurement gas.
The path length is entered into SITRANS SL, preferably using the remote control. The path
length is the distance (l) according to the following figure. For measuring the path length (l)
refer also to Installation of process flanges (Page 43).
O
①
Purging tube
②
Process wall
l Path length
Figure 6-1 Defining the path length