Honeywell Midas-M Sulfur Dioxide (SO2) Sensor, 0-8 ppm, 2 years

Gas Measured	Sulfur Dioxide
Cartridge Part Number	MMS-S2
Sensor Technology	3 electrode electrochemical cell
Measuring Range	SO2	0 ppm to 8 ppm
Default Alarm 1	1 ppm (rising)
Default Alarm 2	2 ppm (rising)
Accuracy	<±5% of measured value
	Exposure to SO2 4 ppm for 5 minutes
Response Time (t62.5)	Typical 7 seconds
Sensor Cartridge Life Expectancy	24 months under typical application conditions
Operating Temperature	0ºC to 40ºC (32ºF to 104ºF)
Effect of Temperature	Zero	< ± 0.01 ppm/ºC
	Sensitivity	< ± 0.4% of measured value/ºC
Operating Humidity (continuous)	15% RH to 90% RH
Effect of Humidity	Zero	No effect
	Sensitivity	< ± 0.5% of measured value/% RH
Operating Pressure	90 kPa to 110 kPa
Effect of Position	No effect in typical application
Long Term Drift	Zero	TBA
	Sensitivity	<10% of measured value/year
Calibration Gas	Sulfur Dioxide (2 ppm to 6 ppm, default 4 ppm)
Challenge Gas (Bump Test)	Sulfur Dioxide (4 ppm)
Warm Up Time	< 10 minutes
Storage Temperature	5°C to 25°C (41°F to 77°F)

Cross Sensitivities

Each Midas-M sensor is potentially cross sensitive to other gases and this may cause a gas reading when exposed to other gases than those originally designated. The table below presents typical readings that will be observed when a new sensor cartridge is exposed to the cross sensitive gas (or a mixture of gases containing the cross sensitive species).

Gas / Vapor	Chemical Formula	Concentration applied (ppm)	Reading (ppm SO2)
Acetylene	C2H2	10	<30
Ammonia	NH3	20	0
Carbon Monoxide	CO	300	<1
Chlorine	CI2	5	<-2
Ethene	C2H4	50	<45
Hydrogen	H2	400	<1
Hydrogen Cyanide	HCN	10	<5
Hydrogen Sulfide	H2S	25	<0.1
Iso Propanol	C3H7OH	3500	1.65
Nitric Oxide	NO	50	0 - 5
Nitrogen Dioxide	NO2	6	<-10
Phosphine	PH3	0.6	1.5
Silane	SiH4	10	8 (Overrange)

Midas-M Sensor Cartridge Quick Reference Guide

Midas-M Sulfur Dioxide Sensor Specifications