I purchased one of these pH Stamps myself. So far I'm pretty impressed by it.
I find the device sends more than just pH values when I send the read "r" command. It output the pH and also the words "base:" and "acid:" followed by a one to three digit number. I'm pretty sure the numbers are the millivolt values. A number following the word "acid:" represents a positive millivolt value while a number after the word "base:" represents a negative millivolt value.
I'm very please to see these millivolt readings. It means it will be possible to use the Propeller to set additional calibration points.
I was very surprised recently to see how big a difference calibrating a pH meter with 1.68 pH buffer and 4.01 pH buffer instead of just 7.00 and 4.01 buffers when measuring the pH 2.00. Using just 7 and 4 buffers in the calibration caused errors as large as 0.2.
My plan is to use a Nordic transceiver to send the pH values wirelessly to my other lab data logging equipment.
I thought I'd let you know I was working on a similar project in case you'd like share notes.
I'll have to see if I have a DS1820 sensor so I can add temperature compensation with it. If I don't use a DS1820, I'll likely use some other temperature sensor.
He Duane , Sorry for my O so late reply . I had been busy with all kind of stuff
about the ph stamp, when i was moving about 3 months ago , i accidently stepped on the ph probe. and broke it of course. That was for the time the end of the ph for a moment .
I did manage to get it working , reading the ph of a watertank , and it did controll a peristaltic pump to adjust the ph , unfortunately for the program also , I had some trouble getting the ukhash virus off my computer with result losing every single file I had , So i had to start all over again.
I didn do anything with the ph & ec stamp anymore, but the day I continue with them is getting close again i think . the stamps did survive
anyway i thout i tell you
I am working on another controller now , monitoring temperture and humidity with a sensiron sht-11 sensor
processing these showing the values on a small screen , a menu interface
and a wiznet w5200 module connected , trying to get a fully web controlable interface , with loginscreen , and dhcp so it will auto set ip enso ,.
id say take a look at my thread , Mike G giving me some great help over ther.
share notes always sounds good to me, ill definitly be intrested to continue the ph& ec monitor
its like the next step to add that to the current controller , giving you the HTML5 web interface , would be nice i think
Comments
How is your project progressing?
I purchased one of these pH Stamps myself. So far I'm pretty impressed by it.
I find the device sends more than just pH values when I send the read "r" command. It output the pH and also the words "base:" and "acid:" followed by a one to three digit number. I'm pretty sure the numbers are the millivolt values. A number following the word "acid:" represents a positive millivolt value while a number after the word "base:" represents a negative millivolt value.
I'm very please to see these millivolt readings. It means it will be possible to use the Propeller to set additional calibration points.
I was very surprised recently to see how big a difference calibrating a pH meter with 1.68 pH buffer and 4.01 pH buffer instead of just 7.00 and 4.01 buffers when measuring the pH 2.00. Using just 7 and 4 buffers in the calibration caused errors as large as 0.2.
My plan is to use a Nordic transceiver to send the pH values wirelessly to my other lab data logging equipment.
I thought I'd let you know I was working on a similar project in case you'd like share notes.
I'll have to see if I have a DS1820 sensor so I can add temperature compensation with it. If I don't use a DS1820, I'll likely use some other temperature sensor.
about the ph stamp, when i was moving about 3 months ago , i accidently stepped on the ph probe. and broke it of course. That was for the time the end of the ph for a moment .
I did manage to get it working , reading the ph of a watertank , and it did controll a peristaltic pump to adjust the ph , unfortunately for the program also , I had some trouble getting the ukhash virus off my computer with result losing every single file I had , So i had to start all over again.
I didn do anything with the ph & ec stamp anymore, but the day I continue with them is getting close again i think . the stamps did survive
anyway i thout i tell you
I am working on another controller now , monitoring temperture and humidity with a sensiron sht-11 sensor
processing these showing the values on a small screen , a menu interface
and a wiznet w5200 module connected , trying to get a fully web controlable interface , with loginscreen , and dhcp so it will auto set ip enso ,.
id say take a look at my thread , Mike G giving me some great help over ther.
share notes always sounds good to me, ill definitly be intrested to continue the ph& ec monitor
its like the next step to add that to the current controller , giving you the HTML5 web interface , would be nice i think