CN-0359 Auto-range feature & accuracy

Question

Hello! This is a follow up to my previous question here: https://ez.analog.com/boston-engineering/f/q-a/117280/cn-0359-accuracy-question 
 It was mentioned by charlyelkhoury that the CN-0359 uses an auto-ranging feature to determine what the sensing range for conductivity will be. In order to determine the accuracy in mS/cm I will need to know what the auto-ranging function is setting the range to. Could someone please tell me where in the CN-0359 firmware this feature is located? 
 Additionally it is stated in the user manual that the accuracy is 0.6% FS. Is this +/- 0.6% or +/-0.3% which would add up to a total of 0.6%? 
 
 Thank you!

rwatson · Accepted Answer

Update on status. 
 Testing with the REV A code showed much better stability and accuracy of the measurement and seems to have largely resolved the drift issue. This combined with carefully watching for air bubbles on the sensor pads and any corrosion of the pads has also improved the repeatability of the measurement. 
 I did notice that when programming the microcontroller a high voltage was applied to the excitation pads and caused a lot of electrolysis to occur until the programming was finished. This does damage the pads of our sensors fairly quickly so we remove the sensor from the liquid when programming. This does not occur if the commands to change the cell constant are sent over serial for example. 
 Over the past few months we integrated our changes for the 10k NTC and created a custom polling command to report back conductivity and temperature from the CN0359. This has all worked well and at this time I consider this ticket to be resolved. Thanks for all the help. 
 
 Here is the related ticket to building the REV A Source code. 
 ez.analog.com/.../cn0359-build-source-code

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CN-0359 Auto-range feature & accuracy

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