PH Automatic Monitors

PH automatic monitors (pHMonitor) comprises  auto sampling, auto calibration and auto alarming. The alarming message may be send out by email, voice call on land line or mobile.

Fig 1. is  pHMonitor.

                               Fig 1. PH automatic monitor

1. Sample Connection

                                            Fig 2. Sample Connection

Sample flows in from sample input (Fig 2.). It passes solenoids controlling valves then stay in measuring cell for sampling (Fig 3.). The sampled data will be stored in CPU. CPU will logged the data and send data to PC by RS232 at the same time. The sample then flows out through Drain output (Fig 2.)

                                                   Fig 3. Display and Calibration

2.  Calibration:

At begin or after certain setting time the system starts self calibration. First water is pumped into measuring cell to clean the cell (Fig 3.). Then PH4 is pumped into the cell and the measuring data is collected by CPU. Afterwards the cell is cleaned by the water and PH10 is pumped into the cell.  PH10 is measured and collected by CPU. Finally the cell is cleaned again by the water. Calibration process finishes.

When sampling PH values are presented by 4-20 mA.

                                           Fig 4. Output Box

 3.    Alarming

                                    Fig  5  alarming system

When PH value is over threshold the out of range relay will activate. At the same time PC will send emails (or/and make calls) to the supervisor. The alarming system activates.

4. Operation procedure.

4.1 Fill pH4, pH10 and water to the pH4, pH10 and water container separately.

4.2 Check All tubes if right after installation.

4.3 Turn on Pump.

4.4 Wait for 1 minute. (Let the pump to build up proper pressure).

4.5 Torn on pHMonitor power.

4.6 pHMonitor may run calibration or  run measuring sample.

4.7 The operation result will be displayed on LCD.

4.8 If PC is connected with pHMonitor by RS232 and pHMonitor_V1.2.exe is running, the history of the operation can be viewed in log.txt located in C:\pHMonitorData\

4.9 Calibration settings.

      Run pHMonitor_V1.2.exe and the following dialog will appear.

                                       Fig. 6           Calibration settings

Calibration PH now if ticked: Tick this box if want calibration.

Interval: Time between calibrations (5% error)

Minimum PH: Out of Range Relay will be activated if sample pH  below this value.

Maximum PH: Out of Range Relay will be activated if sample pH  over this value.

Click Upload Settings if need to update the settings.

4.10 Out of Range Relay

              Fig. 7  Minimum PH < sample pH  < Maximum PH

                    Fig. 8     sample pH  < Minimum PH            OR

                 sample pH  > Maximum PH

4.11 4-20 mA output

                Output 4-20 mA stands for pH4 and pH10.

4.12 4-20 mA connection.

        Note: Max Voltage supply is 30 V.

                     Fig. 9              4-20 mA connected to other application

4-20 mA connection wiring diagram is shown as Fig. 9

5. Application.

pHMonitor is currently used in Tasmania Mine Site.

                                Fig. 10 Installing and Testing on 1^st of May 2007

                                       Fig. 11   pHMonitor is in operation