iChart software has an alarm scheme to provide a number of alerts such as SMS messages, emails, sounds, and display messages. Follow below to trigger an alarm when turbidity sensors indicate miscalibration. The iChart manual contains general information on alarm setup.
1. Open iChart with a current project.
2. Click Project | Setup iChart Alarm.
3. Select the turbidity parameter and click Add.
4. From the Type drop-down menu, select Low threshold.
5. Set the following values: Set Value 1 = -1, Reset Value = -0.9, Count = 2.
- Note: These values are chosen because a negative turbidity reading means that the calibration is bad.
- Set Value is the value which the reading has to go below to trigger the alert.
- Count is the number of times the reading has to cross the Set Value Low threshold to send the alert.
- Reset Value is the value the reading has to go above to reset the count.
Figure 1: Step 4
6. Select the desired alarm action.
7. Click OK.