Altometer
4
Maximum ambient and process temperatures
The compact flowmeter is suitable for ambient temperature range -20 till +60 °C
(DN2,5-15) or -40 till +60 (DN25-100). The process (medium) temperature is limited
to -20 °C for DN2,5-15 and -40°C for DN25-100.
The flowmeter is certified for gas group IIC, temperature classes T6...T3. The
temperature class for gas hazardous areas is determined by the maximum ambient
(T
a
) and process (medium) temperature (T
m
) to following table:
Maximum process (medium) temperature T
m
Temperature class
T
a
=
40 °C
T
a
=
50 °C
T
a
=
60 °C
T6
60 °C
55 °C
not possible
T5
75 °C
75 °C
70 °C
T4
115 °C
115 °C
75 °C
T3
150 °C
135 °C
75 °C
For dust hazardous areas, the maximum surface temperature is equal to the medium
temperature with a minimum of 85 °C.
2 Electrical connection
2.1 General
Warnings:
•
The covers of the housing electronic compartment and the housing itself are
provided with "flameproof" thread. Compared with 'normal' thread the fitting of
"flameproof" thread is relatively tight due to explosion proof requirements.
Therefore screwing on or off of the cover must be done with care, never use
brute force !
•
Keep the threads free of dirt. The thread must be well-greased (with a suitable
teflon grease for example) to make a smooth run possible.
•
For opening of the covers first the "retention" lock must be disabled by means of
a hexagonal socket screwdriver no. 3. After closing of the covers, the "retention
lock" must be enabled again.
•
Before opening of the electronic compartment a delay time after de-energizing
has to be respected:
T6 : at least 35 min., T5: at least 10 min.
