Problems with Calibrating Dissolved Oxygen - Revision history

Dylanp: /* Problems with Calibration */

2009-03-23T00:54:09Z

Problems with Calibration

← Older revision		Revision as of 00:54, 23 March 2009
Line 42:		Line 42:
	Please feel free to contact us if you have additional questions and let us		Please feel free to contact us if you have additional questions and let us
	know if you will be sending in the equipment.		know if you will be sending in the equipment.

	~~---~~

	~~The above steps were carried out. It was verified that the Sonde units had the latest firmware. However, in a solution of NA2SO3, it was reading > 0% DO concentration.~~

	There are three Sonde Units, currently, one of them is calibrated using the steps above, and one of them is not. The unit calibrated with the steps above has DO gain of around 1.25. The one that is not has a DO gain of 1.028. Testing with one of the sondes calibrated with the above procedure yielded a 20% DO reading in water from the chemistry fish tank, while testing with the "uncalibrated" sonde yielded a result of about 10%.

	~~One appears to be uncalibrated entirely.~~

Dylanp: /* Problems with Calibration */

2009-02-12T18:42:46Z

Problems with Calibration

← Older revision		Revision as of 18:42, 12 February 2009
Line 44:		Line 44:

	---		---

			The above steps were carried out. It was verified that the Sonde units had the latest firmware. However, in a solution of NA2SO3, it was reading > 0% DO concentration.

			There are three Sonde Units, currently, one of them is calibrated using the steps above, and one of them is not. The unit calibrated with the steps above has DO gain of around 1.25. The one that is not has a DO gain of 1.028. Testing with one of the sondes calibrated with the above procedure yielded a 20% DO reading in water from the chemistry fish tank, while testing with the "uncalibrated" sonde yielded a result of about 10%.

			One appears to be uncalibrated entirely.

Dylanp at 18:18, 12 February 2009

2009-02-12T18:18:48Z

← Older revision		Revision as of 18:18, 12 February 2009
Line 10:		Line 10:

	Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option, again, using the appropriate atmospheric measurements. This was attempted with both the computer modules we built and the YSI 650-MDS unit.		Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option, again, using the appropriate atmospheric measurements. This was attempted with both the computer modules we built and the YSI 650-MDS unit.

			---

			An email was sent to technical support, which generated the following response:

			Thanks for contacting our company today. If you have tried to calibrate
			dissolved oxygen and your are getting the "out of range" error, there are a
			few things you can check:

			-Make sure the sonde and display have the latest firmware (600R sonde is
			3.06; 650 display is 1.18). This can be downloaded for free from the ysi.com
			website.
			-Remove the old membrane and sand the top of the sensor in one direction.
			-Rinse and dry the sensor.
			-Pour DO electrolyte on the top of the sensor and install a new membrane.
			-Let the sensor warm up for 10-15 minutes and check the readings.
			-DO Charge should be around 50.0 (+/- 25.0)
			-Once you feel the readings have stabilized, enter the calibration menu,
			enter your corrected barometric pressure, and calibrate.
			-If it calibrates, go into the Advanced menu and look at the Cal Constants.
			DO Gain should be around 1.000 (+/- 0.250).


			If it did not calibrate, DO Charge is out of spec, and/or the DO Gain is out
			of spec, there is likely another problem. If could be several different
			things, from the sensor, bulkhead, circuit board, or something else. It
			would be best to send the system into us at this point. We can provide a
			free evaluation and contact you by email with a price quote to get the unit
			back up and running, while meeting factory specs.

			Please feel free to contact us if you have additional questions and let us
			know if you will be sending in the equipment.

			---

Charliep: /* Problems with Calibration */

2008-09-21T17:24:11Z

Problems with Calibration

← Older revision		Revision as of 17:24, 21 September 2008
Line 9:		Line 9:
	The Chemistry department has a tank of water through which oxygen is constantly bubbled through, giving the solution a concentration of 100% Dissolved Oxygen or approximately 8 mg/l. The probe was submerged in the solution and calibrated both with Dissolved Oxygen % and Dissolved Oxygen mg/l with the appropriate atmospheric measurements taken.		The Chemistry department has a tank of water through which oxygen is constantly bubbled through, giving the solution a concentration of 100% Dissolved Oxygen or approximately 8 mg/l. The probe was submerged in the solution and calibrated both with Dissolved Oxygen % and Dissolved Oxygen mg/l with the appropriate atmospheric measurements taken.

	Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option, again, using the appropriate atmospheric measurements. This was attempted with both the computer modules we built and the YSI 650 unit.		Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option, again, using the appropriate atmospheric measurements. This was attempted with both the computer modules we built and the YSI 650-MDS unit.

Dylanp: /* Problems with Calibration */

2008-09-20T17:10:01Z

Problems with Calibration

← Older revision		Revision as of 17:10, 20 September 2008
Line 9:		Line 9:
	The Chemistry department has a tank of water through which oxygen is constantly bubbled through, giving the solution a concentration of 100% Dissolved Oxygen or approximately 8 mg/l. The probe was submerged in the solution and calibrated both with Dissolved Oxygen % and Dissolved Oxygen mg/l with the appropriate atmospheric measurements taken.		The Chemistry department has a tank of water through which oxygen is constantly bubbled through, giving the solution a concentration of 100% Dissolved Oxygen or approximately 8 mg/l. The probe was submerged in the solution and calibrated both with Dissolved Oxygen % and Dissolved Oxygen mg/l with the appropriate atmospheric measurements taken.

	Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option. This was attempted with both the computer modules we built and the YSI 650 unit.		Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option, again, using the appropriate atmospheric measurements. This was attempted with both the computer modules we built and the YSI 650 unit.

Dylanp at 17:09, 20 September 2008

2008-09-20T17:09:22Z

New page

=Problems with Calibration=

Calibrating Dissolved Oxygen has been problematic, and has never worked correctly. Instead of displaying a consistent reading, when submerged in a liquid the probe will at first display a value of either 99% Dissolved Oxygen or -99% Dissolved Oxygen, and after a few seconds of sampling, will start jumping wildly, going from -99% to 50% to -37% to 77%, or following another, similar pattern.

The following techniques were used to calibrate Dissolved Oxygen:

Note that none of them have worked correctly.

The Chemistry department has a tank of water through which oxygen is constantly bubbled through, giving the solution a concentration of 100% Dissolved Oxygen or approximately 8 mg/l. The probe was submerged in the solution and calibrated both with Dissolved Oxygen % and Dissolved Oxygen mg/l with the appropriate atmospheric measurements taken.

Filling the calibration chamber slightly with water, then loosening the top of the chamber to allow for the water to evaporate, then allowing the water to sit for 10 minutes and evaporate, thus saturating the chamber. The probe was then calibrated with the Dissolved Oxygen % option. This was attempted with both the computer modules we built and the YSI 650 unit.