Performing inspection / maintenance
Statically charged door
In certain circumstances, the door can become statically charged.
One possible cause of this is when two non-conducting substances e.g. CTU
gloves (neoprene), see-through door (Makrolon), cleaning cloths (cellulose or
cotton), are rubbed against one another, thus causing static charge to build
up.
Discharging may be slowed down by the ambient conditions, such as dry air
and low external temperatures.
The "G 60 Spezial" test liquid (a hydrocarbon) results in an unusual effect:
A film that looks like a pasty mass, forms on the inside of the see-through
door.
The build-up of static charge counteracts the low surface tension of the
hydrocarbon mixture.
If the same liquid is transferred from a statically charged surface to a surface
with no charge, the liquid will be distributed in the usual manner.
The following points are useful:
- Rinse down the inside of the door with test liquid.
- Adjust the humidity in the surroundings.
- Always clean the disk of the CTU with damp cloths.
- If there is a lot of static, use a commercial anti-static product.
Change the test liquid
Each use of the CTU differs from any other. This means that it is difficult to
define fixed replacement intervals for the test liquid. Determine the
replacement intervals for each application on an individual basis.
Check the test liquid with regard to the following characteristics:
- Odor
- Appearance
(greases, oils, preservatives, water have the effect of clouding the test
liquid or giving it a yellow tint)
- See page 35 for achievable negative control values
CTU 1000 Series
en(us)
Page 70 / 92
BeWa CTU1000 3229578p en-us 2017-04-25.doc
2017-04-25
