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®

Model No.PS-2195

 Specifications

5

More About Calibration

You can also calibrate the Salinity Sensor using a standard salinity solution purchased 
from a company such as Hach (www.hach.com) or Lamotte (www.lamotte.com) that 
offers water quality testing equipment. A third way is to make a calibration solution 
from “Instant Ocean

®

 Sea Salt” (www.instantocean.com) which can be purchased at 

most aquarium supply stores.

Total Dissolved Solids (TDS) and Conductivity

Total dissolved solids (TDS) is a measure of the amount of mineral and salt impurities 
in a sample of water. TDS is usually measured in parts per million (ppm) and drinking 
water is typically below 500 ppm. For example, one kilogram of water containing 1 
milligram of dissolved solids has a TDS of 1 ppm. One way to measure the amount of 
TDS in a sample is to measure the electric conductivity of the sample. 

A conversion factor is used to convert conductivity to the approximate concentration 
of TDS. The conversion factor depends on the specific dissolved solids and can vary 
between 0.40 and 0.96, depending on the dissolved solids. A value of 0.65 is used as 
an approximation if the dissolved solids are not known. As an example, 
TDS (ppm) = 0.65 x Conductivity (

S). Since conductivity varies with temperature, 

the Salinity Sensor has built-in compensation for temperature.

Table: Conversion Chart to Estimate TDS of Aqueous Solutions

 

at 25 °C

Specifications

(*with calibration)

Conductivity 

(

S)

Parts per Million

As Ion

As CaCO

3

As NaCl*

1.000

0.650

0.500

0.400

1.250

0.813

0.625

0.500

1.667

1.083

0.833

0.667

2.500

1.625

1.250

1.000

5.000

3.250

2.500

2.000

10.000

6.500

5.000

4.000

20.000

13.000

10.000

8.000

40.000

26.000

20.000

16.000

80.000

52.000

40.000

32.000

158.730

103.175

79.635

63.492

312.500

203.125

156.250

125.000

625.000

406.250

312.500

250.000

1250.000

812.500

625.000

500.000

2500.000

1625.000

1250.000

1000.000

5000.000

3250.000

2500.000

2000.000

10000.000

6500.000

5000.000

4000.000

Measurement

 Ranges

Other

Values

Conductivity

1,000 to 100,000 

S

Sample rate (maximum)

50 Hz

Temperature

0 to 50 degrees C

Temperature compensation

±0.5 ppt from 0 to 45 °C at 33 ppt

Salinity

1 to 55 ppt ±1%*

Cell constant

10X

Содержание PasPort PS-2195

Страница 1: ...linity Sensor PS 2195 Salinity Sensor Probe 10 X Conductivity Temperature 699 11064 Recommended Items PASPORT Extension Cable PS 2500 PASCO Interface Catalog or web site Data Acquisition Software Cata...

Страница 2: ...ride In the 1970 s salinity was redefined as the conductivity ratio of a water sample to a standard potassium chloride KCl solution Usage One use for the sensor is to explore the salinity of local wat...

Страница 3: ...b site at www pasco com for information 1 When you connect the Salin ity Sensor to the computer through a PASPORT inter face the PASPortal window will launch automatically if DataStudio is not already...

Страница 4: ...ou will need reagent grade sodium chloride salt a liter of distilled or deionized water a stir rod and a container with accurate volume markings Pour 500 milliliters mL of distilled water into the con...

Страница 5: ...on the specific dissolved solids and can vary between 0 40 and 0 96 depending on the dissolved solids A value of 0 65 is used as an approximation if the dissolved solids are not known As an example TD...

Страница 6: ...f PASCO scientific in the United States and or in other countries For more information visit www pasco com legal Windows is a registered trademark of Microsoft Corporation in the United States and or...

Страница 7: ...g more distilled or deionized water until the volume is 200 ml Prepare a 0 005 M sodium hydroxide NaOH solution by dissolving 200 mg of NaOH in 500 ml of distilled or deionized water and then adding d...

Страница 8: ...Remove the Salinity Sensor Probe from the first sample Rinse the end of the probe with distilled water 9 Repeat the data collection process with the other two samples Data Analysis 1 Autoscale the gra...

Страница 9: ...Analysis The table lists typical experimental results In general ionic salts at low to moderate concentrations have a temperature dependence of 2 per degree at 25 C Acids bases and concentrated salt s...

Страница 10: ...Salinity Sensor Notes on the Experiment 10...

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