Millipore Spectroquant Multy Operating Manual page 271

5.8 Calculating the Langelier
saturation index
The Langelier saturation index (LSI) is a measure of the
corrosivity of water.
When the LSI is below –0.5, the water is corrosive, and the
pH and/or alkalinity should be raised.
When the LSI is over 0.5, the water is very hard and there
is a risk of calcification. Here the pH and/or alkalinity should
be reduced.
When the LSI is zero, the water is ideally conditioned.
The following parameters exert an influence on the corrosive
behaviour or, respectively, the water hardness:
• pH
• Temperature
• Calcium hardness
• Acid capacity up to pH 4.3 = total alkalinity =
= alkalinity-m = m value
• TDS = Total dissolved solids (sum of dissolved salts (mg/l))
After determining these parameters, make a note of the
measurement results and enter them into the programme for
calculating the Langelier saturation index as described below.
Setting the temperature unit
The temperature can be entered in degrees Celsius or degrees
Fahrenheit. For this the following presetting procedure must be
carried out (once only):
Press the keys [Mode] [7] [1] in succession.
Confirm your selection by pressing [Enter].
The display now shows:
Pressing the [1] key selects the ° Celsius unit.
Pressing the [2] key selects the ° Fahrenheit unit.
The instrument then returns to the mode menu.
<temperature>
1: °C 2: °F
Chapter 5.8 | Page 1 of 3