The M1000 operates according to the diffusion principle. The monitor is mounted on a flange which is located at the top of the silo or bin. The gas in the atmosphere of the silo diffuses into the oxygen sensor. Since there is no positive movement of chemical powder to the sensor the sampling gas will not block filters and tubing. The right design and choice of components ensures a long term maintenance free operation.

1. M1000
Oxygen Monitor
M1100 Series
Oxygen Monitor
Specialist in preventing dust explosions
The Monox1000 SX.IS Monitor is designed as an in situ oxygen
monitor sensor/transmitter for inert applications in silo’s, trans-
port systems, tanks and bins of for example chemical powders,
which have a potential risk for a dust explosion.
The atmosphere in the silo or bin is inertised with N2 (or CO2)
with the result that due to the low oxygen concentration no ex-
plosions can occur. To ensure that the oxygen gas concentration
is maintained within the specified limits it is necessary to monitor
and control the nitrogen (N2)-dosing process.
Since the environment is mostly very dusty it is not very advisable
to use a sampling system with a pump.
The dust will frequently block the tubing and filters of the sam-
pling system, causing a high level of maintenance. Due to the
patented operating principle of the Monox1000, the chemical
powder does not block the sensor. This results in a very reliable
system and a long term maintenance free operation.
Field of application
SILO’S, BINS, transport systems or other inertised SYSTEMS with
chemical powders, sugar dust, flour that use nitrogen (to prevent
a dust explosion).
Optional
• Automatic Calibration System (product sheet on request)
• UPS, Uninterruptable Power Supply (product sheet on request)
Advantages
• No sampling system required
• No maintenance
• Economic advantage: reduces spillage of nitrogen
• No pumps or filters
• No moving parts
• Significant savings in N2 consumption (at inert systems)
• Increases safety
Successfully installed by
• Momentive Speciality Chemicals
• Shell Chemical Pernis
• Sabic The Netherlands
• Sabic Spain
• Sabic China
• Sabic V.S.
• Cerexagri B.V. / Uniphos
• EMDE Industrie-Technik GmbH
Method of use / Safety recommendations
See manual M1000 & www.steuma.com
Certificates
ATEX: Ex II 2 GD EEx d IIC T4 (Tmax 125°C)
UL classI, div.1, groups A,B,C en D
UL classII, div.1, groups E,F en G

2. Technical Data
The Monox1000 is designed as a 4..20 mA transmitter type instrument with digital dis-
play for the measured oxygen concentration. This concentration is the input for a system
to control the inertisation.
The oxygen sensor is built in a pressure proof and stainless steel housing. The transmitter
housing is made out of aluminium, and is splash waterproof and HF-shielded.
The monitor is mounted on a flange which is located at the top of the silo or bin.
The Monox1000 SX.IS is intrinsically safe according to Ex II 2 GD EEx d IIC T4 (Tmax 125°C)
IP6X with certificate number ISSeP 03ATEX140.
Technical Specifications
Measuring range
0 .. 25% O2
Display
3 ½ digit LCD
Accuracy
+/- 2%
Repeatability
+/- 2% of measuring value
Zero drift
0,5 % / month
Measuring principal
electrochemical
Response time
(T90) < 10 s sensor life ca. 2 year
Temperature range
-15 .. +40 grC
Humidity range
15 .. 99 % R.H., non condensing
Process pressure
+/- 100 mbar compared to atmosphere
Interfering gasses
strongly oxidising gasses, H2 (<-2%), CO (<-0.5%)
Electrical power
24 VDC
Output signal
2-wire, 4 .. 20 mA, linear
Dimensions
180x206x80mm
Weight
2,5 kg
Process flange
standard SS316, 2” ANSI B 16,5 Class 150 Flange
Calibration gas fitting
1/8”NPT
M1000 Series | Oxygen Monitor
AAVOS International bvba – Sparkevaardekenstraat 3, B-8600 Diksmuide Belgium
www.aavos.be info@aavos.be T. +32 (0)51 69 78 15 F. +32 (0)51 69 78 17
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