8
KM26 | MAGNETIC LEVEL GAUGE  |  OI/KM26-EN REV I
Temperature 
class (Ex db)
Max. process 
temperature
Max. surface 
temperature
T6  < 80 °C 85 °C
T5 < 95 °C 100 °C
T4 < 130 °C 135 °C
T3 <195 °C 200 °C
T2 < 295 °C 300 °C
T1 < 445 °C 450 °C
Possible grounding locations with a pipe clamp, pipe strap 
or ring terminal on flange stud.
Figure 5 - Grounding locations
... 2     Safety
Temperature considerations
The KM26 is capable of operation in extreme environments. 
Special consideration must be given to the components 
attached to the KM26 when used at these extremes. 
At high temperatures, scales, switches, and transmitters 
must be protected from the adverse effects of these 
temperatures on their internal components. High 
temperature insulation is frequently used to raise the limits at 
which these devices may operate. This insulation should not 
be removed without adequate replacement. These devices 
rely on proximity with the chamber to operate, therefore any 
replacement insulation should not increase the separation of 
the device from the float. Any additional insulation installed 
should not trap unwanted heat in these devices.
At low temperatures, condensation, frosting, and freezing are 
a concern. Insulation for these conditions is provided as an 
option and in some cases, it is highly recommended. Special 
indicator tubes are made to reduce the effects of cryogenic 
chambers on the indicator. These indicator tubes require 
insulation that can be provided as an option.  
Recommendations for this insulation are included at the end 
of this manual. Low temperatures also cause embrittlement 
of some metals. Chambers and flange bolting must meet the 
temperature specifications. ABB does not recommend 
customer application of cryogenic insulation.
Table 1 - ATEX constructional safety temperature classfication
Temperature classification
Temperature classifications of the ATEX approved KM26 is 
limited to process temperatures up to 50C below the 
maximum surface temperature allowed for each of the 
temperature classes as per the below table. 
ATEX constructional marking
II 2 G c TX (external)  
II 1 G c TX (internal) 
Applicable standards: EN134653-1:2009; EN13463-5:2001
Pressure equipment directive (PED) 
(97/23/CE )
Based on the order, the product shall conform to the EC 
directives listed in the device specific EC declaration of 
conformity. It is designed in accordance with safe engineering 
pratices to meet state of the art safety requirements, has 
been tested and left the factory in a condition in which they 
are safe to operate.
Storage and handling information
To prevent damage to the shipping tubes and / or crates that 
the level gauges are transported in, these items should not be 
over-exposed to inclement weather. The KM26 magnetic level 
gauge should be stored in such a manner that would not 
allow the indicator tube to be immersed or submerged in any 
liquid. Sufficient precautions should be taken so that the 
glass or polycarbonate indicator tubes are not broken or 
damaged. There are no special storage requirements for the 
EC chamber themselves, but if there is a transmitter and / or 
switch, the storage requirements of the transmitter and / or 
switch must be met. See data sheets for specific requirement. 
•  after unpacking the, inspect it for damage.
•  check the packaging for accessories.
•  during intermediate storage or transport, only store the 
level gauge in the original packaging.
•  if required, storage prior to installation should be indoors 
at ambient temperatures, not to exceed ambient 
conditions as specified in the individual datasheet of the 
accessories. 
For information on permissible ambient conditions for 
storage and transport, refer to the specification section of 
the datasheet. Although there is no limit on the duration of 
storage, the warranty conditions stipulated on the supplier’s 
order of acknowledgement still applies.