ph probe sensitivity

[kirkwood]

I got my ph probe calibrated with 7/10 solution correctly a few days ago. It is giving my reading of 7.95 with lights off to 8.12 with lights on. Yesterday when my ph probe was reading at 7.95, I tested with my very reliable ELOS test kit and it was reporting at 8.20. So I'm really not sure what the issue is with the ph probe especially considering that I just calibrated it.

[lnevo]

7.95 to 8.12 is good for a daily spread. I'm usually in exactly that range.

How accurate can you consider a test kit that relies on subjective measurements of fluids drops and color comparison, and reagents that expire over time...

Either way your only talking about a difference of .25

What's important with ph monitoring is your stability and watching for any significant changes.

I would test with another digital meter if possible and compare, but regardless I wouldn't worry overly much.

[jjdezek]

I had my original unit and PH read right around 7.9 - 8.0 without calibration. then i had a water change mishap and got the head unit and wifi wet. got new replacement board and reprogramed everything and PH was reading at around 10.6 so i got some calibration fluid and now its reading steady at 6.99 is it possible for the PH probe to be messed up?

[rimai]

What were the numbers you got in the calibration process?

[jjdezek]

Are you talking what numbers showed on the screen when it was in the solution? That was 888-889 in both solutions.

[rimai]

Those look wrong.

[jjdezek]

I didn't think it was. Did I do it wrong. I pushed the calibrate PH probe and placed it in solution 7 first and numbers stayed at 888-889 for about 30 sec to a min. Then pressed ok and put in solution 10 with same results.

[jjdezek]

Just tried it again and after I was done I put it in the 10 solution to see what it would read and it stayed at 6.99 I also unplugged it and it still read 6.99. Then I put it in a cup of top off water that has baking soda added to it and it still reading6.99

[lnevo]

Stupid question, but you did take the plastic bottle off of the probe, right?

[jjdezek]

lol yes i did.

[rimai]

The numbers should have been close to 540 and 830. Not 888
If you don't see that difference, your reading can't detect differences either.
It could be the probe. Does the bulb look intact? No cracks/shattered?
If you go into calibration mode, remove the pH probe and short out the inside pin with the outer shell of BNC connector, what number do you get?
pH 7 is a neutral solution that generates 0mV. Shorting out the connector forces it to be 0mV.

[jjdezek]

It stays at 887 when I touch a wire to center pin hole and outer case.

[jjdezek]

Is something with my code not allowing it to read or is my main board bad?

[jjdezek]

Code: Select all

#include <ReefAngel_Features.h>
#include <Globals.h>
#include <RA_Wifi.h>
#include <Wire.h>
#include <OneWire.h>
#include <Time.h>
#include <DS1307RTC.h>
#include <InternalEEPROM.h>
#include <RA_NokiaLCD.h>
#include <RA_ATO.h>
#include <RA_Joystick.h>
#include <LED.h>
#include <RA_TempSensor.h>
#include <Relay.h>
#include <RA_PWM.h>
#include <Timer.h>
#include <Memory.h>
#include <InternalEEPROM.h>
#include <RA_Colors.h>
#include <RA_CustomColors.h>
#include <Salinity.h>
#include <RF.h>
#include <IO.h>
#include <ORP.h>
#include <AI.h>
#include <PH.h>
#include <WaterLevel.h>
#include <Humidity.h>
#include <DCPump.h>
#include <ReefAngel.h>

////// Place global variable code below here
#define NUMBERS_8x16
void DrawCustomMain()
{
// the graph is drawn/updated when we exit the main menu &
// when the parameters are saved
ReefAngel.LCD.DrawDate(6, 112);
ReefAngel.LCD.DrawText(COLOR_INDIGO, COLOR_WHITE,25,5, "Jeremy's Reef");
pingSerial();

DrawStatus (20,80);
DrawParams (5,40);
DrawParamsa (0,10);
pingSerial();
byte TempRelay = ReefAngel.Relay.RelayData;
TempRelay &= ReefAngel.Relay.RelayMaskOff;
TempRelay |= ReefAngel.Relay.RelayMaskOn;
ReefAngel.LCD.DrawOutletBox(12, 93, TempRelay);
}

////// Place global variable code above here


void setup()
{
    // This must be the first line
    ReefAngel.Init();  //Initialize controller
    // Ports toggled in Feeding Mode
    ReefAngel.FeedingModePorts = Port5Bit | Port6Bit;
    // Ports toggled in Water Change Mode
    ReefAngel.WaterChangePorts = Port1Bit;
    // Ports toggled when Lights On / Off menu entry selected
    ReefAngel.LightsOnPorts = 0;
    // Ports turned off when Overheat temperature exceeded
    ReefAngel.OverheatShutoffPorts = Port3Bit | Port7Bit;
    // Use T1 probe as temperature and overheat functions
    ReefAngel.TempProbe = T1_PROBE;
    ReefAngel.OverheatProbe = T1_PROBE;
    // Set the Overheat temperature setting
    InternalMemory.OverheatTemp_write( 800 );

    // Feeeding and Water Change mode speed
    ReefAngel.DCPump.FeedingSpeed=0;
    ReefAngel.DCPump.WaterChangeSpeed=0;


    // Ports that are always on
    ReefAngel.Relay.On( Port2 );
    ReefAngel.Relay.On( Port4 );
    ReefAngel.Relay.On( Port8 );

    ////// Place additional initialization code below here
    

    ////// Place additional initialization code above here
}

void loop()
{
    ReefAngel.StandardATO( Port1,60 );
    ReefAngel.StandardLights( Port3,18,0,10,0 );
    ReefAngel.Wavemaker( Port5,60 );
    ReefAngel.Wavemaker( Port6,60 );
    ReefAngel.StandardHeater( Port7,751,761 );
    ReefAngel.DCPump.DaylightChannel = AntiSync;
    ReefAngel.DCPump.ActinicChannel = Sync;
    ReefAngel.DCPump.ExpansionChannel[0] = None;
    ReefAngel.DCPump.ExpansionChannel[1] = None;
    ReefAngel.DCPump.ExpansionChannel[2] = None;
    ReefAngel.DCPump.ExpansionChannel[3] = None;
    ReefAngel.DCPump.ExpansionChannel[4] = None;
    ReefAngel.DCPump.ExpansionChannel[5] = None;
    ////// Place your custom code below here
      if (ReefAngel.DCPump.Mode==Custom)
  {
  ReefAngel.PWM.SetDaylight( NutrientTransportMode(50,100,2000,true) ); // Nutrient Transport on sync mode
  ReefAngel.PWM.SetActinic( NutrientTransportMode(50,100,2000,false) ); // Nutrient Transport on anti-sync mode


  }


    ////// Place your custom code above here

    // This should always be the last line
    ReefAngel.Portal( "jjdezek" );
    ReefAngel.ShowInterface();
}

void DrawParamsa(int x, int y){
char buf[16];
  ReefAngel.LCD.DrawText(DPColor,DefaultBGColor,x+40,y+10,"WP40L:");
ReefAngel.LCD.DrawSingleMonitor(ReefAngel.PWM.GetDaylightValue(), DPColor, x+78, y+10,1);
ReefAngel.LCD.DrawText(APColor,DefaultBGColor,x+40,y+20,"WP40R:");
ReefAngel.LCD.DrawSingleMonitor(ReefAngel.PWM.GetActinicValue(),APColor, x+78, y+20,1);

}

void DrawParams(int x, int y) {
  char buf[16];

  ReefAngel.LCD.DrawText(COLOR_BLACK,DefaultBGColor,x+5,y,"Temp:");
  ReefAngel.LCD.DrawText(COLOR_BLACK,DefaultBGColor,x+80, y, "PH:");
  // Temp and PH
  y+=10;

  ConvertNumToString(buf, ReefAngel.Params.Temp[T1_PROBE], 10);
  ReefAngel.LCD.DrawLargeText(T1TempColor, DefaultBGColor, x+5, y, buf, Num8x16);
  ConvertNumToString(buf, ReefAngel.Params.PH, 100);
  ReefAngel.LCD.DrawLargeText(PHColor, DefaultBGColor, x+80, y, buf, Num8x16);
  y+=5;

}

void DrawStatus(int x, int y) {
  int t=x;
  
  ReefAngel.LCD.DrawLargeText(COLOR_INDIGO,DefaultBGColor,15,y,"High",Font8x16);
  ReefAngel.LCD.DrawLargeText(COLOR_INDIGO,DefaultBGColor,85,y,"Low",Font8x16);
  
  if (ReefAngel.HighATO.IsActive()) {
    ReefAngel.LCD.FillCircle(55,y+3,5,COLOR_GREEN);
  } else {
    ReefAngel.LCD.FillCircle(55,y+3,5,COLOR_RED);
  }
  
  if (ReefAngel.LowATO.IsActive()) {
    ReefAngel.LCD.FillCircle(70,y+3,5,COLOR_GREEN);
  } else {
    ReefAngel.LCD.FillCircle(70,y+3,5,COLOR_RED);
  }
}

void DrawCustomGraph()
{
}

[kirkwood]

The numbers should have been close to 540 and 830. Not 888
If you don't see that difference, your reading can't detect differences either.
It could be the probe. Does the bulb look intact? No cracks/shattered?
If you go into calibration mode, remove the pH probe and short out the inside pin with the outer shell of BNC connector, what number do you get?
pH 7 is a neutral solution that generates 0mV. Shorting out the connector forces it to be 0mV.

Is there a way to see what the numbers were from the previous time the probe was calibrated? 540 and 830 sound close to the range I got, but I'm curious to see where my numbers were. I just calibrated mine a few days ago and feel like my readings are a bit on the low side and that the consistency of the readings is a bit off. I calibrated with 7/10 solution from BRS.

And to validate Inevo's previous question, I was running my probe with the bottle attached for a good month.

[rimai]

You can use the Client or android app to read the memory locations.
Or you can also use web browser.
http://ipaddress:2000/mi231 - for pH10
http://ipaddress:2000/mi833 - for pH7

[rimai]

Is something with my code not allowing it to read or is my main board bad?

If the readings don't go to around 540 when shorted out, it could be the board.

[jjdezek]

Is something with my code not allowing it to read or is my main board bad?

If the readings don't go to around 540 when shorted out, it could be the board.

what would cause the board to be bad? Rare manufacture defect? I just got it from you like a month ago.

[rimai]

They are tested individually, so I'm not sure what caused it to start giving you wrong readings.
You will need to send it back for analysis.