09-2018
file: ISAFE3-OperationManual_EN_DE.R4.VEXH.docx
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Vallen ISAFE3 Operation Manual - Operation Manual
9
Installation
9.1
General hints
The applicable standards for intrinsic safety installations, especially EN 60079-14:2008 and
EN 60079-25:2010 must be considered for intrinsically safe installations. Since SISO3 is an
isolating barrier, severe requirements for non-isolating barriers do not apply. For example, it is
not required to connect the intrinsically safe circuit at the signal isolator side to earth and it is
also not required to use an isolating transformer before each mains powered device on the safe
side of the installation (EN 60079-14:2008 / 12.3).
Beside of safety considerations, AE-experts have to provide AE-specific test procedures, e.g. to
define sensor locations and maximum sensor distances. These considerations are not topic of
this document.
Additional standards and rules may have to be considered for other aspects.
9.2
Sensor mounting
– functional requirements
Sensor ISAS3 shall pick up very small surface movements in a pm range (1 pm = 10
-12
m). The
location for installing an AE sensor must be flat and clean. For best acoustic coupling a
diameter of at least 25
mm shall be free from painting/coating for direct contact of the face of
ISAS3 (14 mm diameter) to the test object. A coupling agent shall be used between face of
ISAS3 and test object. For a permanent installation, a cold hardening silicon rubber, e.g.
RTV162, is recommended as coupling agent. It also protects the area of removed coating
against corrosion. RTV162 needs about 24 hours for curing. For temporary installations, silicon
grease or other proven coupling materials can be used.
The sensitive face of ISAS3 must be pressed onto the surface of the test object with a constant
force of at least 60 N. The magnetic holder MAG4IS is one example how this can be achieved
for a temporary installation. Chapter 8.2
“ISAS3-SpecMount” shows details for a replacement of
the 3 magnets by 3 bolts that can be welded to the test object for a permanent sensor
installation.
9.3
Cabling between sensor ISAS3 and SISO3 (Ex i)
We recommend two types of 50 Ω coaxial cable:
RG58C/U, if the cable will not come in contact with oil.
E&E 29392-1, an ETFE cable that can come into contact with crude oil.
Cable parameters and maximal cable length (2 km) are listed under 5.2.5.
For mounting SMA connectors see the assembly instructions in Figure 11-1 (ISAS3 side) and
Figure 11-2 (SISO3 side).
For sealing the cable-to-sensor transition against 12 bar peak pressure, see chapter 8.3 and
8.4.
For use on deck of a ship or at a tank car we recommend to protect the connector by using a
normal heat shrink material that is less costly than RW200-E.
