SO2-A40 pages

Dioxide
SO2-A4 Sulfur Dioxide Sensor
4-Electrode
4-Electrode

Technical Specification

Figure 1 SO2-A4 Schematic Diagram

Patented

All dimensions in millimetres (± 0.15mm)

Top View
PERFORMANCE

Bottom View
Sensitivity
Response time
Zero current
Noise*
Range
Linearity
Overgas limit

Side View

nA/ppm at 2ppm SO2
t90 (s) from zero to 2ppm SO2
nA in zero air at 20°C
±2 standard deviations (ppb equivalent)
ppm limit of performance warranty
ppb error at 20ppm SO2, linear at zero and 2ppm SO2
maximum ppm for stable response to gas pulse

320 to 480
< 20
5 to 45
15
50
0 to -5
100

* Tested with Alphasense AFE low noise circuit

LIFETIME

Zero drift
Sensitivity drift
Operating life

ppb equivalent change/year in lab air
% change/year in lab air, monthly test
months until 50% original signal (24 month warranted)

ENVIRONMENTAL Sensitivity @ -20°C
Sensitivity @ 50°C
Zero @ -20°C
Zero @ 50°C

(% output @ -20°C/output @ 20°C) @ 2ppm SO2
(% output @ 50°C/output @ 20°C) @ 2ppm SO2
nA change from 20°C
nA change from 20°C

CROSS
SENSITIVITY

ppm·hrs
% measured gas
% measured gas
% measured gas
% measured gas
% measured gas
% measured gas
% measured gas
% measured gas
% measured gas

Filter capacity
H2S sensitivity
NO2 sensitivity
Cl2
sensitivity
NO sensitivity
CO sensitivity
H2
sensitivity
C2H4 sensitivity
NH3 sensitivity
CO2 sensitivity

KEY
Temperature range
SPECIFICATIONS Pressure range
Humidity range
Storage period
Load Resistor
Weight

@ 5ppm
@ 5ppm
@ 5ppm
@ 5ppm
@ 5ppm
@ 100ppm
@ 100ppm
@ 20ppm
@ 5%

< ±20
< ±15
> 36
80 to 95
90 to 105
< ± 25
150 to 300
450
< 40
< -160
< -70
< -1.5
<2
<1
<1
< 0.1
< 0.1

H2S
NO2
Cl2
NO
CO
H2
C2 H 4
NH3
CO2

°C
kPa
% rh continuous (see note below)
months @ 3 to 20°C (stored in sealed pot)
Ω (AFE circuit is recommended)
g

-30 to 50
80 to 120
15 to 90
6
33 to 100
<6

Note: Above 85% rh and 40oC a maximum continuous exposure period of 10 days is warranted. Where such exposure occurs the sensor will
recover normal electrolyte volumes when allowed to rest at lower % rh and temperature levels for several days.
At the end of the product’s life, do not dispose of any electronic sensor, component or instrument in the domestic waste, but contact the
instrument manufacturer, Alphasense or its distributor for disposal instructions.
NOTE: all sensors are tested at ambient environmental conditions, with 47 ohm load resistor, unless otherwise stated. As applications of use are outside our control, the
information provided is given without legal responsibility. Customers should test under their own conditions, to ensure that the sensors are suitable for their own requirements.
Alphasense Ltd, Sensor Technology House, 300 Avenue West, Skyline 120, Great Notley. CM77 7AA. UK
Telephone: +44 (0) 1376 556 700 Fax: +44 (0) 1376 335 899 E-mail: sensors@alphasense.com Website: www.alphasense.com