Libelium Plug & Sense Smart water ions erroneous

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Mon Aug 20, 2018 4:27 pm

Hi,

I am using smart water ions with PRO sensors(ph with temperature sensor) and I have started with calibarating even before my experiment(new sensor) and it is not showing the correct results.

This is the program that I have used as below with a pH 7.0 solution:

#include <smartWaterIons.h>
// Calibration values
#define cal_point_10 1.405
#define cal_point_7 2.048
#define cal_point_4 2.687

// Temperature at which calibration was carried out
#define cal_temp 25.0
socket1Class pHSensor; //<------ Define the connection SOCKET
pt1000Class temperatureSensor;

void setup()
{
// Configure the calibration points
pHSensor.setpHCalibrationPoints(cal_point_10, cal_point_7, cal_point_4, cal_temp);

// Turn ON the Smart Water Ions Sensor Board and start the USB
SWIonsBoard.ON();
USB.ON();
}
void loop()
{
// Read the pH sensor
float pHVoltage = pHSensor.read();

// Read the temperature sensor
float temperature = temperatureSensor.read();

// Print the output values
USB.print(F("pH value: "));
USB.print(pHVoltage);
USB.print(F("volts | "));

USB.print(F(" temperature: "));
USB.print(temperature);
USB.print(F("degrees | "));

// Convert the value read with the information obtained in calibration
float pHValue = pHSensor.pHConversion(pHVoltage, temperature);
USB.print(F(" pH Estimated: "));
USB.println(pHValue);
}


The output I am getting is as follows: [Evenif I kept it for 2-4 hours]

pH value: 1.6631999969volts | temperature: 21.8796081542degrees | pH Estimated: 8.8005352020
pH value: 1.1965999603volts | temperature: 21.9494323730degrees | pH Estimated: 10.9835662841
pH value: 0.7635662555volts | temperature: 21.8967895507degrees | pH Estimated: 13.0099554061
pH value: 0.3579599857volts | temperature: 21.9142761230degrees | pH Estimated: 14.9076881408
pH value: 0.0103643751volts | temperature: 21.9313964843degrees | pH Estimated: 16.5339336395
pH value: 0.0017790625volts | temperature: 21.9478149414degrees | pH Estimated: 16.5739574432
pH value: 0.0018181249volts | temperature: 21.9649047851degrees | pH Estimated: 16.5736236572
pH value: 0.0018124999volts | temperature: 21.9142761230degrees | pH Estimated: 16.5741004943
pH value: 0.0017162500volts | temperature: 21.9140625000degrees | pH Estimated: 16.5745506286
pH value: 0.0016534375volts | temperature: 21.9147033691degrees | pH Estimated: 16.5748405456
pH value: 0.0017500000volts | temperature: 21.9140625000degrees | pH Estimated: 16.5743942260
pH value: 0.0017834374volts | temperature: 21.8959655761degrees | pH Estimated: 16.5743980407
pH value: 0.0016250000volts | temperature: 21.9329223632degrees | pH Estimated: 16.5748100280

Could you please help me to sort out the problem?

Thanks,
Varsha

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Re: Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Mon Aug 20, 2018 4:51 pm

API is v033 and the battery is currenly 98%. I have connected the pH sensor probe to socket1 and temperature to the temperature socket.I also tried it with the ph solution 10.0, still its showing the same.

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Libelium Plug & Sense Smart water ions erroneous

Post by libelium-dev » Tue Aug 21, 2018 10:20 am

Hi,

Please repeat the calibration process of the sensor following the technical guide in page 42. First time calibration will take some time until output stabilization.

Once you let the probe working on each calibration solution and take note of the output voltage you should change the calibration values of the code and the calibration temperature.

Don't hesitate to ask if you have more doubts.

Regards

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Re: Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Tue Aug 21, 2018 11:42 am

Hi,

Thankyou for your reply. I followed the technical guide that you have mentioned and tried it with ph 7 and 10, waited for around 2-3 hours for the calibration and both time it were showing similar output(voltage ~0.0050 and ph ~16.570000). So how long should I wait to get a stabilized output?


Thanks,
Varsha

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Libelium Plug & Sense Smart water ions erroneous

Post by libelium-dev » Tue Aug 21, 2018 1:38 pm

Hi,

2-3 hours should be fine for first time calibration, then you should write at the code the output voltage after repeat the process with the three calibration solutions.

Regards.

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Re: Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Wed Aug 22, 2018 3:37 pm

Hi,

I tried the calibaration with ph 10 and modified the temperature in cod to 20 and ca_point_10 to 1.150 for 3 hours and the result seems to be same as follows:
pH value: 0.0015909375volts | temperature: 22.4857482910degrees | pH Estimated: 13.8253097534
pH value: 0.0014375000volts | temperature: 22.4855041503degrees | pH Estimated: 13.8258237838
pH value: 0.0015000000volts | temperature: 22.4520568847degrees | pH Estimated: 13.8257656097
pH value: 0.0016250000volts | temperature: 22.4849853515degrees | pH Estimated: 13.8252000808
pH value: 0.0015625000volts | temperature: 22.5021057128degrees | pH Estimated: 13.8253307342

Could you please help me out?

Regards,
Varsha

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Libelium Plug & Sense Smart water ions erroneous

Post by libelium-dev » Thu Aug 23, 2018 7:46 am

Hi,

Did you made the same with the other calibration solutions?

Regards

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Re: Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Tue Aug 28, 2018 11:26 am

Hi,
When I tried with the calibaration solution 7.0, the result was as follows:

pH value: 1.6631999969volts | temperature: 21.8796081542degrees | pH Estimated: 8.8005352020
pH value: 1.1965999603volts | temperature: 21.9494323730degrees | pH Estimated: 10.9835662841
pH value: 0.7635662555volts | temperature: 21.8967895507degrees | pH Estimated: 13.0099554061
pH value: 0.3579599857volts | temperature: 21.9142761230degrees | pH Estimated: 14.9076881408
pH value: 0.0103643751volts | temperature: 21.9313964843degrees | pH Estimated: 16.5339336395
pH value: 0.0017790625volts | temperature: 21.9478149414degrees | pH Estimated: 16.5739574432
pH value: 0.0018181249volts | temperature: 21.9649047851degrees | pH Estimated: 16.5736236572
pH value: 0.0018124999volts | temperature: 21.9142761230degrees | pH Estimated: 16.5741004943
pH value: 0.0017162500volts | temperature: 21.9140625000degrees | pH Estimated: 16.5745506286

Regards,
Varsha

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Libelium Plug & Sense Smart water ions erroneous

Post by libelium-dev » Tue Aug 28, 2018 1:01 pm

Hi,

Could you share with us a complete log of your calibration process?

Are you using a reference probe too? (Ph sensor + reference)

Remember clean the sensors when you go to change the calibration liquid.

Regards,

varsha6006
Posts: 15
Joined: Thu Mar 01, 2018 5:21 pm
Company: Birminghamcity univ

Re: Libelium Plug & Sense Smart water ions erroneous

Post by varsha6006 » Tue Aug 28, 2018 1:42 pm

Hi,

For the calibration, I used only the ph and temperature sensor along with the calibration solution(ph 10) connected to the smart water ions board. The code were uploaded (with a modified temperature setting to 20 and ca_point to 1.150) and waited for 3 hours to get a stable reading. When changing the calibration solutions, everytime I cleaned the sensors using DI water as mentioned in the technical guide.

https://drive.google.com/open?id=1SUAVl ... dvA6UIQc4u

https://drive.google.com/open?id=1W-xdc ... 3YeGKCTYJV

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest