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ph probe sensitivity
Posted: Sun Jun 23, 2013 6:09 am
by 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.
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 7:08 am
by 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.
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 5:21 pm
by 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?
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 8:06 pm
by rimai
What were the numbers you got in the calibration process?
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 8:08 pm
by jjdezek
Are you talking what numbers showed on the screen when it was in the solution? That was 888-889 in both solutions.
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 8:12 pm
by rimai
Those look wrong.
Re: ph probe sensitivity
Posted: Sun Jun 23, 2013 8:14 pm
by 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.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 5:11 am
by 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
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 5:23 am
by lnevo
Stupid question, but you did take the plastic bottle off of the probe, right?
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 5:41 am
by jjdezek
lol yes i did.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 8:07 am
by 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.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 8:31 am
by jjdezek
It stays at 887 when I touch a wire to center pin hole and outer case.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 8:33 am
by jjdezek
Is something with my code not allowing it to read or is my main board bad?
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 8:36 am
by 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()
{
}
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 10:24 am
by kirkwood
rimai wrote: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.

Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 10:39 am
by 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
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 10:40 am
by rimai
jjdezek wrote: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.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 10:49 am
by jjdezek
rimai wrote:jjdezek wrote: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.
Re: ph probe sensitivity
Posted: Mon Jun 24, 2013 2:48 pm
by 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.