KROHNE IFC 110 Converter - Manual (Page 67)

Part C Special applications, functional checks, service, and order numbers Sect. 6.10
05/2003 IFC 110 F 67
Changes on A/D converter PCB, see illustration in Section 8.7
Switch off the power supply before opening the housing !
1) Remove the glass cover from the control compartment (remove 4 screws).
2) Remove the cover from the terminal compartment (remove 2 screws).
3) Pull all plug-in terminals out of the sockets inside the terminal compartment.
4) Remove 4 screws from the front panel, take hold of the handle on the upper end of the front
panel and carefully pull the complete electronic unit out of the signal converter housing.
5) Put down the electronic unit with the front panel F facing down.
6) Unscrew the two S
LP
screws from the printed circuit boards FSV (field current supply) and
ADC (analog/digital converter) and carefully pull both PCBs out of their plug bases (see
illustration in Section 8.7).
7) Loosen the common plug-and-socket connection.
8) The circuit side of the ADC circuit board has 4 soldering points S1-S4
(two semicircles, each - see illustration in Section 8.7).
Carefully scratch the protective lacquer off the soldering points which are used. Do not
remove the protective lacquer from soldering point S3. Do not damage the conductive tracks.
9) Connect the semicircles of soldering points which are used with tin solder.
10) Re-assemble in reverse order (items 7 to 2).
11) For LA / S2 (empty tube stabilization) and LA / S4 (electrode cleaning and empty tube
stabilization), check the setting of the low-flow cutoff SMU, Fct. 1.03, and reset if necessary:
L.F.Cutoff switched on, range: Full scale range Q
100%
Cutoff ...... values
... OFF ... ... ON ...
> 3 m/s > 10 ft/s > 2 % 1 %
1 – 3 m/s 3 -10 ft/s > 6 % 4 %
< 1 m/s < 3 ft/s > 10 % 8 %