Select A Solution; Temperature Compensation - Hach MP-4 User Manual

Operation
Push the pH key.
5.
Observe or record the value displayed, or push UP/MS to store the reading.
6.
Important Note: After the test, fill the pH/ORP sensor cup with pH Storage Solution
and replace the protective cap. Do not allow the pH/ORP sensor cup to dry out.

3.11 Select a solution

Conductivity, resistivity and TDS (including mineral/salt) require temperature
compensation to 25 °C. The solution profile selection determines the temperature
compensation of conductivity and calculation of TDS and mineral/salt from
compensated conductivity.
There are four solution types:
KCl
•
NaCl
•
442
•
User
•
On the left side of the display is the salt solution characteristic used to model
temperature compensation of conductivity and its TDS conversion. By default, KCI
is used for conductivity, NaCl is used for resistivity (and mineral/salt), and 442
(natural water characteristic) is used for TDS. The User selection allows a custom
value to be entered for the temperature compensation of conductivity and the
conversion ratio if measuring TDS.
Check the display to see if the solution profile displayed is the solution type desired
for that measurement. To change a solution:
Push the COND key, the RES key, the MIN/SALT key or the TDS key to select
1.
the parameter to change the solution type.
Push and hold the CAL/MCLR key for three seconds and wait for SEL to
2.
appear in the display.
Push UP/MS or MR/DOWN to scroll to the desired solution type.
3.
Push the CAL/MCLR key to accept the new solution.
4.

3.11.1Temperature compensation

Electrical conductivity indicates solution concentration and ionization of the
dissolved material. Because temperature affects ionization, conductivity
measurements change with temperature and must be corrected to read at 25
Temperature compensation uses the characteristics of salt solutions. The selected
salt solution is displayed on the left side of the display. By default, the meter uses
KCl for conductivity, NaCl for resistivity and 442 for TDS (see
51).
The User mode customizes the temperature compensation and the conversion ratio
if measuring TDS.
Note: Calibration of each solution type is performed separately and calibration of one solution
does not affect the calibration of the other solution types.
C.
º
Appendix B on page
19