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Technical Support

 PS-3204

9

013-14662B

15.

Click 

Next

.

16.

Click 

Finish

. Rinse and dry the probe before using it 

for data measurement.

Theory of Calibration

One of the functions of the PASCO Data Collection 
Software is to take the stream of raw data from a sensor 
and transform it into the calibrated data that you see in the 
Graph, Table, and other displays. If you do not calibrate a 
sensor yourself, the software uses a default calibration that 
is loaded when the sensor is connected.

You can think of the software as taking in raw data and 
outputing calibrated data. When you perform a calibration, 
the software redefines the linear equation that transforms 
the raw input data into the calibrated output data. The linear 
function is of the form:

Raw Input = Slope x Calibrated Offset

Or:

Calibrated Output = (Raw Input - Offset)/Slope

The function can be represented graphically as a line.

Two points, Pt 1 and Pt 2, define the line. In the two-point 
calibration procedure, each point is reset by associating a 
known standard value (for instance, the pH of a buffer 
solution) with a raw input measurement that the sensor 
sends to the GLX when it is in that standard. In a one-point 
calibration, only one of the points is reset by the user.

Types of Calibration

There are three types of calibration: two-point, one-point 
slope, and one-point offset. Any of these calibrations can 
be performed on a single sensor, or simultaneously on 
multiple similar sensors; however, for any given sensor, the 
software will automatically select the most typical 
calibration type as the default setting.

Two-Point

In a two-point calibration, you reset two points to define a 
new line. This type of calibration affects both the slope and 
the offset. 

One-Point Slope

In a one-point slope calibration, you reset only one point. 
The slope of the line changes so that the line intersects the 
new point, while the offset (or Y-intercept) does not change. 

One-Point Offset

In a one-point offset calibration, you reset only one point. 
The line shifts so that it intersects the new point, but its 
slope does not change.

Offset calibration is usually used to make one sensor agree 
with another sensor. Due to normal variation among 
probes, a second probe might read consistently higher than 
the first probe. Normally this difference would be 
insignificant; however, an offset calibration can be used to 
bring the sensors into closer alignment.

Содержание PS-3204

Страница 1: ...n one can be connected to a computer or tablet at the same time The pH Sensor can also be used with alternative probes such as Ion Selective Electrodes ISE and the Oxidation Reduction Potent ORP Probe...

Страница 2: ...connector Twist the probe s BNC connector clockwise left to right about one quarter turn to lock it in place To remove the pH Probe from the Wireless pH Sensor reverse the process NOTE When removing t...

Страница 3: ...e pH Probe in the solution to be measured The bulb shaped glass membrane should be entirely immersed 3 Press or click start or record to begin recording data 4 Wait for the reading to stabilize 5 Rins...

Страница 4: ...or application If the problem remains press and hold the ON button for ten seconds and then release the button Turn on the sensor in the usual way Turn Bluetooth off and then turn it back on Retry pH...

Страница 5: ...es training in the safe handling of flammable caustic and corrosive chemicals and a working knowledge of serial solution and calibration procedures Suggested Experiments Practically any experiment tha...

Страница 6: ...ary by country and region It is your responsibility to recycle your electronic equipment per your local environmental laws and regulations to ensure that it will be recycled in a manner that protects...

Страница 7: ...hing lower than 0x6 means an older version of Bluetooth Your device will need the PS 3500 USB Bluetooth 4 0 Adapter 1 The Mac Mini and MacBook Air were updated with Bluetooth SMART support in 2011 The...

Страница 8: ...in distilled water and then put the pH Probe into a pH 4 buffer solution 7 Under Calibration Point 1 click the Standard Value box and enter the known value 4 00 in this example 8 Under Calibration Po...

Страница 9: ...nt that the sensor sends to the GLX when it is in that standard In a one point calibration only one of the points is reset by the user Types of Calibration There are three types of calibration two poi...

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