55
Optional Device Installation
6.
Press
CHANGE CHOICE
to select temperature units (°C, °F).
Press
ACCEPT
.
7.5.4 Conductivity Probe Calibration
1.
From the Main Menu, select
OPTIONS > ADVANCED OPTIONS > CALIBRATION >
CONDUCTIVITY.
2.
Clean and dry the probe.
3.
Place the sensor and thermometer in the calibration solution. The temperature
sensor is located in the middle of the sensor body allowing the probe to be
completely submerged in the solution.
4.
Allow the sensor to stabilize in the solution about 10 minutes to ensure that the probe
and the solution are the same temperature.
5.
Enter the temperature correction factor or enter zero (0) for no correction factor.
Note:
The temperature correction factor is used to compensate for the effects of temperature on the
conductivity readings at the point of installation. The conductivity of a solution is temperature
sensitive. Therefore the actual conductivity of the solution will change with the temperature. Each
site may have a different correction factor depending on the major constituent of the flow stream.
This is not used for calibration and has no effect on the calibration of the sensor. Below are some
examples of compensation factors of various liquids.
•
0.96%/°C 5% Sulfuric Acid
•
1.88%/°C Dilute Ammonia
•
1.91%/°C ‘Typical’ Wastewater
•
1.97%/°C Potassium Chloride
•
2.12%/°C Salt (Sodium Chloride)
•
2.84%/°C 98% Sulfuric Acid
•
4.55%/°C Ultra-pure Water
6.
With the sensor still in the calibration solution, press any key. Wait for the sensor to
stabilize. Calculate the actual conductivity of the calibration solution. If using the KCl
solution provided by the manufacturer, make your selection from
. If using a solution other than
1.0 mS @ 25 °C KCl available from the manufacturer, you must calculate the
conductivity of the solution using temperature correction factors. See the example
below.
Example:
The KCl calibration solution is 1.0 mS. at 25°C. The temperature correction factor for KCl
is 1.97%/°C. If the actual temperature of the KCl at the time of calibration is 18.4 °C, then
the solution has a conductivity value of 0.870 mS.
a.
Find the difference between the labeled temperature and the actual temperature
of the calibration solution at the time of calibration.
25 °C – 18.4 °C = 6.6 °C
b.
Multiply the difference (6.6) by the correction factor per °C (1.97% or 0.0197).
6.6 °C x 0.0197/°C = 0.13002
c.
If the calibration temperature is lower than the labeled value, then subtract that
value from the standard (1.0 mS) to get the actual value to be used for calibration.
1.0 mS - (correction factor) 0.13002 = 0.86998 mS
d.
If the calibration temperature is higher than the labeled value, then add that value
to the standard (1.0 mS) to get the actual value to be used for calibration.
Содержание Sigma 950
Страница 2: ......
Страница 6: ...4...
Страница 20: ...18 Introduction...
Страница 34: ...32 Basic Programming Setup...
Страница 50: ...48 Sensor Installation...
Страница 82: ...80 Maintenance...
Страница 83: ...81 Appendix A Program Flow Charts Figure 22 Overview of Basic Program Menus...
Страница 84: ...82 Program Flow Charts Figure 23 Setup Flow Chart...
Страница 85: ...83 Program Flow Charts Figure 24 Options Flow Chart...
Страница 86: ...84 Program Flow Charts Figure 25 Alarms Menus Flow Chart...
Страница 87: ...85 Program Flow Charts Figure 26 Calibration Menus Flow Chart Page 1...
Страница 88: ...86 Program Flow Charts...
Страница 102: ...100 Programming Features...
Страница 106: ...104 Primary Devices Head Measurement Locations...
Страница 126: ...124 SCADA Modbus System Guidelines...