Measuring kalkwasser saturation with a TDS meter

[jhans1]

I tried measuring supposedly saturated kalkwasser with my TDS meter (TDS-3 from HM Digital). I got a reading of 260 x10 (2600ppm).
According to other threads on this forum a fully saturated kalkwasser solution should read approx. 5150ppm TDS.

I also tried to put 2 teaspoons of kalk in a glass of water. This should ensure a fully saturated sample. My TDS meter is still reading max 2600 ppm.

Is my TDS meter defective?

 

[Randy Holmes-Farley Verified Community Expert]

How high can your meter read? What happens in seawater?

 

[jhans1]

How high can your meter read? What happens in seawater?

Seawater from tank @ 35 ppt reads 550 x 10 (TDS 5500)

• TDS Range: 0 – 9990 ppm (mg/L)
• Temp. Range: 0 – 80 degrees Celsius
• Resolution: 0-999: 1 ppm; 1000-9990: 10 ppm (indicated by a ‘x10’ icon)
• Temperature Resolution: 0.1 degree Celsius (Celsius only)
• Accuracy: +/- 2%
• EC-to-TDS Conversion Factor: NaCl (avg. 0.5)
• ATC: Built-in sensor for Automatic Temperature Compensation of 1 to 50 degrees Celsius (33 to 122 degrees Fahrenheit)
• Power source: 2 x 1.5V button cell batteries (included) (LR44 or equivalent)
• Battery life: 1000 hours of usage
• Dimensions: 15.5 x 3.1 x 2.3cm (6.1 x 1.25 x 1 inches)
• Weight with case: 76.5g (2.7 oz)
• Weight without case: 56.7g (2 oz)

 

[Randy Holmes-Farley Verified Community Expert]

Seawater from tank @ 35 ppt reads 550 x 10 (TDS 5500)

• TDS Range: 0 – 9990 ppm (mg/L)
• Temp. Range: 0 – 80 degrees Celsius
• Resolution: 0-999: 1 ppm; 1000-9990: 10 ppm (indicated by a ‘x10’ icon)
• Temperature Resolution: 0.1 degree Celsius (Celsius only)
• Accuracy: +/- 2%
• EC-to-TDS Conversion Factor: NaCl (avg. 0.5)
• ATC: Built-in sensor for Automatic Temperature Compensation of 1 to 50 degrees Celsius (33 to 122 degrees Fahrenheit)
• Power source: 2 x 1.5V button cell batteries (included) (LR44 or equivalent)
• Battery life: 1000 hours of usage
• Dimensions: 15.5 x 3.1 x 2.3cm (6.1 x 1.25 x 1 inches)
• Weight with case: 76.5g (2.7 oz)
• Weight without case: 56.7g (2 oz)

OK, so it is reading low. Seawater will have maxed it out since it is way, way above 10,000 ppm TDS.

My suggestion is to ignore that absolute value and just look to relative readings, using a true saturated solution as you made as the standard, and compare all other limewater solutions to it.

 

[jhans1]

OK, so it is reading low. Seawater will have maxed it out since it is way, way above 10,000 ppm TDS.

My suggestion is to ignore that absolute value and just look to relative readings, using a true saturated solution as you made as the standard, and compare all other limewater solutions to it.

Makes sense. Thanks!