Vermason 225208 Installation, Operation And Maintenance

SINGLE CONTINUOUS MONITOR FOR
WRIST STRAP AND BENCHMAT
Installation, Operation and Maintenance
Figure 1. 225208 Single Continuous
Monitor.
Description
The 225208 continuous monitoring
system provides constant monitoring
of personnel and work surface
grounding. It operates using a
current loop and dual wrist strap
system. It uses a low-test voltage
and current which makes it suitable
for use with most ESD sensitive
items. The unit is unaffected by
capacitance variations associated
with personnel and environmental
conditions. It is suitable for use in
some clean rooms. The resistance
thresholds are set to meet the
requirements of EN 61340-5-1 but
they can be altered if required.
Leading companies use continuous
monitors as a cost effective
component in satisfying some of the
audit and check requirements of EN
61340-5-1. Wrist strap testing
"Where continuous monitoring is
used, no additional testing is
required." (EN 61340-1, per A.5.2)
"The wrist band will normally be worn
for several hours at a time so it
needs to be comfortable while
making good contact with the skin. It
is a good idea to check the wrist
strap every time it is applied.
Constant on line monitors can be
used to that any breaks will be
immediately found." (EN 61340-5-2
section 5.2.7)
Phone: 0044 (0) 1462 672005, Fax: 0044 (0) 1462 670440 • e-mail: Service@Vermason.co.uk, Internet: Vermason.co.uk
TB-7562 December 2008 Page 1 of 2
TECHNICAL BULLETIN TB-7562
Inspection
Remove the test unit from the carton
and inspect for shipping damages.
Each 225208 unit should include the
following:
1 Single Continuous monitoring
unit, item #225207
1 Dual fabric wrist band
1 Dual cord for dual wrist band
1 Remote connecting box (with a
monitored socket and guest
connection) complete with
mounting screws
2 mat grounding cords, 2.5m
long, 10 mm socket / 4mm
banana plug
1 monitor grounding cord,
2.5m long, 4mm plug/ring
terminal
1 Power supply UK
1 Screws, adhesive hook and loop
straps for mounting monitor
1 Washers, studs, screws for
connecting to bench top
Installation
1. Determine the mounting location of
the monitor (225207) and remote
boxes (225204). The monitor can
easily be mounted on top of the
work surface or underneath a shelf
using double-sided adhesive hook
and loop straps, or the supplied
screws. The front panel should be
readily visible to the operators.
The remote box should be
mounted in an easily accessible
position, as the operator has to be
connected to this box.
2. Wire the remote boxes to the
monitor by connecting the stereo
jack plug to the jack socket
mounted on the back panel of the
monitor. This cord provides a path
to ground for the monitored wrist
strap socket and the guest socket,
as well as the monitoring signal.
The picture on the right shows
how to connect the remote boxes
to the back panel of the
instrument.
3. Mount two 10 mm press-studs on
the work surface about 5 cm
apart. Two types of press-studs
UNIT C, 4TH DIMENSION, FOURTH AVENUE, LETCHWORTH, HERTS, SG6 2TD UK
are included with the kit; choose
the most convenient one for your
surface. If using hard laminate
ensure that both press-studs are
making connection with the
conductive layer. It is generally
good to use the supplied rubber
washer to ensure optimum
connection, whatever the type of
surface. Place it under the stud
on the surface.
4. It is possible to connect the mats
in two different ways:
Solution 1: connect one stud to
the earth and the other to the
monitor.
Note: The earth loop is monitored
with this method of wiring, if the
earth cord is disconnected, the
instrument will alarm
Figure 2. 225208 Wiring Solution 1.
Solution 2: Connect both
studs on the mat to the
monitor using two 230385
cords.
Note: The earth loop is not
monitored with this method of
wiring. If the earth cord is
disconnected, the instrument will
not alarm. However, the two mat
testing circuits are fully
independent.
Use only this wiring solution if the
bench top resistance is very high
and the standard connection
method does not provide
satisfactory results. With this
method, the earth cord must be
hard-wired and tested regularly.
© 2008 Vermason
Made in Britain