Operation Manual VISATRON® VN115/87plus EX
06/2016
Page 31
SCHALLER AUTOMATION
D-66440 Blieskastel / Saarland / Germany / Industriering 14 / P.O Box 1280
Industrielle Automationstechnik GmbH & Co. KG
Tel. +49(0)6842-508
-
0
/ Fax -260 / eMail: [email protected] / www.schaller.de
CAUTION! Do not fill in more than 70ml; the excess oil can
remove the required oil in the siphon by a physical suction
effect through the draining channel.
3.4
Adjusting the sensitivity of the OMD
The detector determines the oil mist concentration by an optical measurement. The
calculated values have the unit 'opacity'. 100% opacity means that no light is
transmitted through the oil mist sample. This is equivalent to a complete white
wall.
The LEL (Lower Explosion Level) is equal to 47mg/l oil mist concentration in air at a
temperature of 25 °C. IACS UR M67 rules do request that OMD
’s
do indicate an oil
mist alarm latest at approx. 2.5mg/l. The lesser sensitivity level of all VN/87plus
OMD’s, level 6, still ensures an Oil Mist Alarm at oil mist concentrations inside the
engine of <2.5mg/l. This complies fully with the requirements given by the IACS
UR M67.
Position
Relative VN115 alarm
level in opacity
3
1.5%
4
2.0%
5
3.0%
6
5.0%
Table 2:
Sensitivity switch position and corresponding oil mist alarm level
Standard switch position 3 or 4 normally should be sufficient
for all sorts of engines. However if necessary, choose the
lower sensitivity level 5 or 6.
The sensitivity of the VISATRON® oil mist detector can be adjusted by a switch on
the rear side of the measuring head (see
Figure 29: Sensitivity switch at rear side of measuring head
Sensitivity
Switch
