Explosion Hazards Arising From Gas And Dust - Endress+Hauser Proline Promass 200 Safety Instructions

Proline Promass 200
Explosion hazards arising
from gas and dust
10
Determining the temperature class and surface temperature with the temperature
table
• In the case of gas: Determine the temperature class as a function of the ambient
temperature T and the medium temperature T
a
• In the case of dust: Determine the maximum surface temperature as a function of the
maximum ambient temperature T
Example of the maximum surface temperature for explosion hazards arising from dust
Device: Promass F 200, compact version, DN 25 mm
Maximum ambient temperature: T
Maximum medium temperature: T
Basic specification, Position 3 (Output) = C
Ta
Sensor type
[°C]
35
Promas E 200
50
60
35
Promass F 200
50
60
Promass F 200 T = 60
a
Abb. 1: Procedure for determining the maximum surface temperature
Procedure for determining the maximum surface temperature:
1. Select the device (Promass F 200), nominal diameter (DN 25) and ambient temperature
T (60 °C) in the associated temperature table (compact version). The row showing the
a
maximum medium temperature is determined.
2. Select the maximum medium temperature T
the maximum medium temperature of a cell. The column with the temperature class for
gas is determined (130 °C → T4).
The maximum temperature of the temperature class determined corresponds to the
maximum surface temperature: T4 = 135 °C = maximum surface temperature for dust.
.
m
and the maximum medium temperature T
a
= 60 °C
a
= 98 °C
m
T6 T5
[85 °C] [100 °C] [135 °C]
50 95
-- 95
-- --
50 95
-- 95
-- --
T = 130
°C
m
( 98 °C) £
(98 °C), which is smaller than or equal to
m
T4 T3 T2
[200 °C] [300 °C]
130 140 140
130 140 140
130 140 140
130 150 150
130 150 150
130 150 150
°C
.
m
T1
[450 °C]
140
140
140
150
150
150