CMA ML63m User guide

Brand: CMA

Model: ML63m

Type: User guide

OXYGENGASSENSORML63M

USER’SGUIDE



CENTRE FOR MICROCOMPUTER APPLICATIONS

http://www.cma-science.nl

2|ML63mOxygenGasSensorUser’sGuide

Shortdescription

The Oxygen Gas sensor ML63m measures the gaseous oxygen concentration in the

rangeof0to100%.Itusesanelectrochemicalcell,whichcontainsaleadanode.The

anodeandcathodeareimmersedinanelectrolyte.Whenoxygenmoleculesenterthe

cell,theygetelectrochemicallyreducedatthecathode.This

electrochemicalreaction

generates a current that is proportional to the partial pressure of oxygen in the gas

mixture. The current is measured across a resistance to generate a small voltage

output. The voltage output is amplified to the 0 .. 5V output range and digitized via

theanalogtodigital

converterpresentonthesensorboard.



The Oxygen Gas sensor is an I2C digital sensor, which gives calibrated values of the

measured quantity. This sensor can only be connected to special interfaces that

supportI2CdigitalsensorsliketheCMAMoLabinterface.

Sensorspecifications

TheOxygenGassensorML63misa digitalsensorthatconvertsthe measuredoxygen

level in % to a digital value via 16‐bit analog‐to‐digital conversion. The maximal

samplingrateoftheOxygenGassensoris1Hz.

Collectingdata

This Oxygen Gas sensor works only with specific interfaces. The sensor will be

automaticallydetectedwhenconnectedtosuchaninterface.Fordetailedinformation

aboutmeasurementswithsensorsconsulttheUserManualsoftheinterfaceandthe

Coach6software.

Calibration

TheOxygenGassensorissuppliedwithafactorycalibrationforoxygengaslevelsin%.

The Coach 6 program allows shifting the pre‐defined calibration if needed. The use r

calibrationisstoredinnon‐volatileusersensormemory.

Since the sensor shows some drift over its lifetime, for precise absolute



measurementsitisadvisedtocalibratethesensorbeforeuse.UseforexampletheSet

tovalueoptiontoadjustacalibrationpointofoxygenlevelinair(in0%RHthis value

is20.9%).

AtmosphericConsiderations

Because the % ofoxygen varies with the  amount of water vapor in the atmosphere,

you may want to adjust your atmospheric oxygen calibration value to improve

accuracy when using the Oxygen Gas Sensor. The accepted value of 20.9% for

atmospheric oxygen levels is calculated in dry air (0% humidity). If

 you know the

relative humidityofthelocationatwhichyouare calibrating,you cansubstituteone

ML63mOxygenGasSensorUser’sGuide |3

ofthevaluesbelowinplaceof20.9%.



Relative Humidity 0% 25 % 50% 75% 100%

Oxygen in % by volume 20.9 20.7 20.5 20.3 20.1



Additionaltips

 Veryimportant:Donotplacethesensorintoanyliquid.Thesensorisintended

onlyformeasuringgaseous,notaqueous,O

concentration.

 EventhoughthesensorrespondsratherquicklytochangesinO

concentration,

rememberthatgashastodiffuseintotheelectrochemicalcelllocatedatthetopof

thesensorshaftbeforeanychangesinconcentrationcanbedetected.Since

diffusionofgasesisafairlyslowprocess,therecanbesomedelayinreadings.

 Thesensorelementhasalimited

operatinglifeofabout6yearsinopenair.

 Theelectrolyteinthesensorelementhassimilardangersasbatteries.The

electrolyteshowsweakacidityandcontainsheavymetals.

Neverdismantlethesensor.Whenskinisexposedtotheelectrolyteimmediately

rinsewithwaterandseekmedicalattention.

Suggestedexperiments

TheOxygenGassensorcanbeusedtomonitorgaseousoxygen inavarietyofbiology

andchemistryexperimentssuchas:

 Monitoringhumanrespiration.

 Monitoringchangesinoxygenconcentrationduringphotosynthesisandrespiration

ofplants.

 Monitoringrespirationofanimals,insects,orgerminatingseeds.

 Monitoringoxidationofmetals

suchasiron.

 Monitoringconsumptionofoxygenbyyeastduringrespirationofsugars.



4|ML63mOxygenGasSensorUser’sGuide

TechnicalSpecifications



Sensorkind Digital16‐bitsresolution

(on‐sensordigitalconversion)

communicationviaI2C

Measuringrange 0..100%

Resolution 0.00153%

Maximalsamplingrate

1Hz

Operationtemperature 0~50°C

Operatinghumidityrange 0~95%RH,noncondensing

Respondtime

90%offullscalereadingin30s

Gassamplingmode

Diffusionthroughasolidmembrane

Sensorelementoperatinglife

6yearsat20.9%O2,25

C,50%RH

Linearity

99.99% offullscaleatconstanttemperatureand

pressure

Storagetemperature

0~50

Sensordimensions

Housing:37 x 18 x 16 mm (W xDxH)

Connection 5‐pinsminijackplug



Warranty:

TheOxygenGassensorML63miswarrantedtobefreefromdefectsinmaterialsand

workmanshipfor a periodof12monthsfromthedateofpurchaseprovidedthatithas

been used under normal laboratory conditions. This warranty does not apply if the

sensorhasbeendamagedbyaccidentor

misuse.



Note:Thisproductistobeusedforeducationalpurposesonly.Itisnotappropriatefor 

industrial,medical,research,orcommercialapplications.    

Rev. 10/06/2012

CMA ML63m User guide

CMA ML63m User guide

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