Siemens ULTRAMAT 23, Manual, Page: 80 / 244

Commissioning
6.2 Safety instructions
ULTRAMAT 23
80
Manual, 3/2016, A5E37100388-003
6.2.5 Use in biogas plants
6.2.5.1 Safety information
DANGER
Danger of poisoning
This device is designed to measure hydrogen sulfide and dihydrogen sulfide, H
2
S)!
Hydrogen sulfide is highly toxic even in small concentrations! The odor threshold for
hydrogen sulfide is very low at 0.02 vpm (20 vpb), but higher concentrations result in
numbing of the olfactory receptors in the nose so that the odor is no longer perceived.
Persons exposed to this gas in concentrations up to 100 vpm for several hours exhibit
symptoms of poisoning such as fatigue, headaches, lack of appetite, lack of concentration,
irritation of the mucous membranes of eyes and respiratory tract, and throat irritations.
Inhalation of H
2
S concentrations of 500 vpm longer than 30 minutes can cause fatal
poisoning. Concentrations above 1 000 vpm cause death within a few minutes,
concentrations above 5 000 vpm cause death within a few seconds!
When using this device in plant where there may be high concentrations of H
2
S and you
therefore need to take following continual precautions to prevent the effects of poisoning:
•
Connect the gas outlet of the analyzer to a gas exhaust unit so that no gas can escape
into the environment!
• Before you begin maintenance on the analyzer, make sure that the H
2
S concentration in
the analyzer is close to 0 vpm. Before beginning work, always flush the gas path of the
analyzer and the gas sampler with ambient air or nitrogen for a duration of about 10
minutes .
•
Check for leaks in the analyzer at regular intervals!
DANGER
Danger of explosion
This device is used in biogas plants, among other places. When it is used in biogas plants,
you should expect that the sample gas will contain methane, which forms explosive
mixtures with oxygen or air in certain concentrations. These conditions are possible with
certain operating states of the plant.