TPS hydroCHEM User manual
Congratulations !
The hydroCHEM is a high quality, precision Conductivity and pH controller and is designed for
maximum reliability to give you many years of service.
Despite its impressive list of features, the hydroCHEM is a breeze to operate. This manual has
been designed to help you get started, and also contains some handy application tips. If at any
stage you require assistance, please contact either your local TPS representative or the TPS factory
in Brisbane.
The manual is divided into the following sections:
1. Table of Contents
Each major section of the handbook is clearly listed. Sub-sections have also been included to
enable you to find the information you need at a glance.
2. Introduction
The introduction has a diagram and explanation of the display and controls of the
hydroCHEM. It also contains a full listing of all of the items that you should have received
with the unit. Please take the time to read this section, as it explains some of items that are
mentioned in subsequent sections.
3. Main Section
The main section of the handbook provides complete details of the hydroCHEM, including
operating modes, calibration, troubleshooting, specifications, and warranty terms.
4. Appendices
Appendices containing background information and application notes are provided at the back
of this manual.
TPS Pty Ltd
4 Jamberoo Street
Springwood, Brisbane,
Australia, 4127
Phone : (07) 32 900 400
International : 61 7 32 900 400
Fax : (07) 3808 4871
International : 61 7 3808 4871
E-mail : [email protected]
Web Site : www.tps.com.au
hydroCHEM
Conductivity and pH
Controller
Date :14-Jan-2003
Author :MS
Version :3.21
1
Contents
1. Introduction........................................................................................................................................3
1.1 hydroCHEM Display and Controls.................................................................................................................3
1.2 hydroCHEM Connectors................................................................................................................................3
1.3 Menu Key......................................................................................................................................................4
1.4 Function Keys................................................................................................................................................4
1.5 Enter Key ......................................................................................................................................................4
1.6 Help Key.......................................................................................................................................................4
1.7 Shift Key.......................................................................................................................................................4
1.8 Arrow Keys...................................................................................................................................................4
1.9 80 Character Display......................................................................................................................................4
1.10 Unpacking Information..............................................................................................................................5
1.11 hydroCHEM Menu Structure.....................................................................................................................6
2. Limits Set-up ......................................................................................................................................7
2.1 Setting the Control Limits..............................................................................................................................7
2.2 Control Direction...........................................................................................................................................7
2.3 Control Sensitivity.........................................................................................................................................8
2.4 Control Limit Set-up examples.......................................................................................................................9
2.5 Alarms......................................................................................................................................................... 10
3. Control Set-up ..................................................................................................................................14
3.1 Setting up the Conductivity control function................................................................................................. 14
3.2 Setting up the pH control function................................................................................................................15
3.3 Selecting Automatic Control or Standby Modes............................................................................................15
4. Quick-Dose Function........................................................................................................................16
5. Flow Sensing....................................................................................................................................17
5.1 hydroCHEM-DS Flow Sensing ....................................................................................................................17
5.2 hydroCHEM Flow Sensing .......................................................................................................................... 18
6. Temperature Calibration ..................................................................................................................19
6.1 Temperature Calibration Procedure.............................................................................................................. 19
6.2 Temperature Calibration Notes.....................................................................................................................19
6.3 Temperature Calibration Messages............................................................................................................... 19
7. Conductivity Calibration ..................................................................................................................20
7.1 Conductivity Calibration Procedure..............................................................................................................20
7.2Conductivity Calibration Notes ....................................................................................................................21
7.3 Conductivity Calibration Messages .............................................................................................................. 21
8. TDS Calibration ................................................................................................................................22
8.1 TDS Calibration Procedure .......................................................................................................................... 22
8.2 TDS Calibration Notes.................................................................................................................................23
8.3 TDS Calibration Messages........................................................................................................................... 23
9. pH Calibration...................................................................................................................................24
9.1 pH Calibration Procedure.............................................................................................................................24
9.2 pH Calibration Notes ...................................................................................................................................25
9.3 pH Calibration Messages..............................................................................................................................26
10. Setting up the Sample Chamber......................................................................................................27
10.1 Connecting the tubing.............................................................................................................................. 27
10.2 Adjusting the Flow Rate.......................................................................................................................... 28
11. Peristaltic Pumps .............................................................................................................................29
11.1 Commissioning the Peristaltic Pumps ...................................................................................................... 29
11.2 Lubricating the Pump Tubing .................................................................................................................. 30
11.3 Replacing the Pump Tubing..................................................................................................................... 31
12. Control Outputs................................................................................................................................32
12.1 Output Cable Connections.......................................................................................................................32
12.2 Control Output Specifications.................................................................................................................. 32
13. Password Security ...........................................................................................................................32
13.1 Enabling the Password Security function. ................................................................................................32
13.2 Using the Password Security function......................................................................................................33
13.3 Changing the Password............................................................................................................................33
13.4 Disabling the Password Security function ................................................................................................33
2
14. Good Laboratory Practices (GLP) ...................................................................................................34
14.1 Recalling Calibration information on the display......................................................................................34
14.2 Printing Calibration information to the RS232 Port ..................................................................................35
14.3 Recalling System information on the display............................................................................................ 35
14.4 Printing System information to the RS232 Port........................................................................................ 38
14.5 Failed Calibration.................................................................................................................................... 39
14.6 Instrument Serial Number........................................................................................................................39
14.7 Additional GLP Features......................................................................................................................... 39
15. Datalogging Function.......................................................................................................................40
15.1 Recording readings manually................................................................................................................... 40
15.2 Recording readings automatically............................................................................................................ 40
15.3 Recalling Readings from the Notepad......................................................................................................41
15.4 Erasing Records from the Notepad...........................................................................................................42
15.5 Printing Records from the Notepad to the RS232 Port..............................................................................42
16. RS232 Port........................................................................................................................................43
16.1 Setting the Baud Rate.............................................................................................................................. 43
16.2 Sending Readings to the RS232 Port........................................................................................................ 43
16.3 RS232 Configuration...............................................................................................................................43
16.4 Communication and Statistical Software..................................................................................................43
16.5 Commands.............................................................................................................................................. 44
16.6 Data Format ............................................................................................................................................45
16.7 GLP Data Format....................................................................................................................................47
16.8 Importing Data into Microsoft Excel........................................................................................................48
17. Setting the Clock..............................................................................................................................50
18. Selecting the Conductivity/TDS units..............................................................................................51
19. Selecting Display Resolution...........................................................................................................51
20. Emergency ShutOFF timer...............................................................................................................52
20.1 Procedure in event of ShutOFF timer being tripped.................................................................................. 52
21. Selecting Buffers for Auto Buffer Recognition...............................................................................53
22. Resetting the hydroCHEM................................................................................................................54
22.1 Resetting the Calibration information only...............................................................................................54
22.2 Resetting the Full System information .....................................................................................................54
22.3 Factory Default System Settings.............................................................................................................. 55
23. Instrument firmware version number..............................................................................................55
24. Troubleshooting...............................................................................................................................56
24.1 General Errors.........................................................................................................................................56
24.2 Conductivity / TDS Troubleshooting .......................................................................................................57
24.3 pH Troubleshooting................................................................................................................................. 58
24.4 Temperature Troubleshooting..................................................................................................................58
24.5 Pump Troubleshooting ............................................................................................................................58
25. Appendices.......................................................................................................................................59
25.1 Mounting the hydroCHEM ......................................................................................................................59
25.2 Care and Cleaning of Conductivity Sensors..............................................................................................59
25.3 pH Electrode Fundamentals..................................................................................................................... 60
25.4 hydroCHEM Specifications .....................................................................................................................62
26. Warranty ...........................................................................................................................................64
3
1. Introduction
1.1 hydroCHEM Display and Controls
1.2 hydroCHEM Connectors
4
1.3 Menu Key
•Press the key to access the user-friendly menu system.
•Press the key to quit without saving changes when entering data.
1.4 Function Keys
•Press the to function keys to select desired options within the menu system.
•These keys perform the following function directly in normal display mode…
:Press to record readings into the Notepad, when the Plus-Pack is fitted. See section 15.
:Press to transmit current reading plus date and time to the RS232 port, when the Plus-
Pack is fitted. See section 16.2.
•Press the to to enter a password when the security function is enabled. See section 12.
1.5 Enter Key
Press the key to accept default values or save changes when entering data.
1.6 Help Key
Press the key to obtain context-sensitive help messages.
1.7 Shift Key
•Press the key to alternate between standard display and large digit display. See section 1.9.
•Press and hold the key while scrolling data with the and keys to speed up the
scrolling rate.
1.8 Arrow Keys
•Press the and keys to scroll values up and down when entering or displaying data.
•Press the and keys to move the cursor left and right when setting the calendar clock,
when Plus-Pack is fitted. See section 17.
1.9 80 Character Display
•80 character alphanumeric display with user-friendly menu and context-sensitive help system.
•Standard display mode shows Conductivity and pH data, limits and control status. Temperature
data is also displayed. The current time is displayed when Plus-Pack is fitted. For example…
1.8mS/cm (2.0) 6.6pH (6.5) 22.0oc
Adding Wait:300 12:00
•Large digit mode shows Conductivity and pH in double height digits. Control status and
Temperature data are displayed in standard digits. The current time is displayed in standard
digits when Plus-Pack is fitted. For example…
5
1.10 Unpacking Information
Before using your new hydroCHEM, please check that the following accessories have been
included:
Part No
Standard hydroCHEM Kit…
1. hydroCHEM Hydroponics Controller................... 111103
2. 4 Terminal Conductivity Sensor, 5m cable............. 122215
3. Gel-filled Submersible pH Sensor, 5m cable.......... 111224
4. Inductive pump sensor........................................... 130102
5. pH4.00 Buffer, 200mL........................................... 121381
6. pH6.88 Buffer, 200mL........................................... 121306
7. 2.76mS/cm Conductivity Standard, 200mL............ 122306
8. Control output cable for A, B and pH Pumps......... 130105
9. 24V DC Plug-Pack Power Supply.......................... 130106
(or other to suit country of destination)
10. hydroCHEM Handbook........................................ 130050
hydroCHEM-DS Kit .................................................... 111109
1. hydroCHEM Hydroponics Controller................... 111103
(Pre-fitted onto mounting panel)
2. Dosing panel with 3 peristaltic pumps and............. 116320
sample chamber
3. 4 Terminal Conductivity Sensor............................. 122205
4. Gel-filled pH Sensor.............................................. 121227
5. pH4.00 Buffer, 200mL........................................... 121381
6. pH6.88 Buffer, 200mL........................................... 121306
7. 2.76mS/cm Conductivity Standard, 200mL............ 122306
8. 24V DC Plug-Pack Power Supply.......................... 130106
(or other to suit country of destination)
9. 2 metres of Semi-rigid Input Tubing...................... 116358
10. 2 metres of Flexible Output Tubing ....................... 116360
11. 3 x weights for feed drums for each pump.............. 116354
12. 10 metres of 13mm Black Poly Tubing.................. NPH.5
13. 4 x 13mm Poly Tube Clips..................................... NC13
14. hydroCHEM Handbook........................................ 130050
Options that may have been ordered with your hydroCHEM…
1. Plus-Pack option (includes RS232 cable)............... 130100
2. Communication software for Windows 95 & 98 .... 130086
Other spares…
1. Peristaltic Pump tube replacement assembly.......... 116352
2. Syringe of Lubricant for Peristaltic Pump Tubing.. 130103
3. RS232 Interface Cable........................................... 130041
6
1.11 hydroCHEM Menu Structure
A detailed breakdown of the menu system of the hydroCHEM is shown below. This diagram
provides a quick reference for the menu functions available for the hydroCHEM.
→F1:Calibrate →F1:Conductivity
or: F1:TDS
F2:pH
F3:Temperature
→F2:Control →F1:Auto
or: F1:Standby
F2:Quick Dose
F3:Conductivity
F4:pH
→F3:Limits →F1:Set Limits
F2:Direction
F3:Sensitivity →F1:Fine
F2:Medium
F3:Coarse
F4:Alarms F1:Enable/Disable
F2:Set Alarm
Margins
F3:Set Alarm
Delay Times
→F4:Logger →F1:Recall
F2:Erase →F1:Erase All
F2:Erase Last
F3:Print
F4:Program
F5:Enable
or: F5:Disable
→F5:System →F1:Password →F1:Change Code
F3:Enable Security
& Enter Code
or: F3:Disable Security
F2:GLP →F1:Recall Cal.
F2:Print Cal.
F3:Recall Sys.
F4:Print Sys.
F3:Clock
F4:Baud →F1:300
F2:9600
F3:19200
F5:Setup →F1:Units →F1:mS/cm
F2:ppK (TDS)
F3:CF
F4:dS/M
F2:Resolution →F1:Low
F2:High
F3:ShutOFF
F4:Buffer →Select pH buffers
F5:Initialise →F1:Calibration only
F2:Full System
Functions in shaded cells are available when the Plus-Pack option is fitted.
7
2. Limits Set-up
The limits must be set to the required values before attempting to use the hydroCHEM for
automatic control.
2.1 Setting the Control Limits
1. Select the Limits menu ( →→ F3:Limits).
2. Select F1:Set limits from the menu. The current Conductivity limit is displayed. For
example…
Enter Conductivity Limit : 2.0 mS/cm
Use the and keys to set the Conductivity limit. The allowable range is 0.0 to 9.9 mS/cm.
Press to save the new value, or press to quit without saving the changes.
3. The current pH limit is now displayed. For example…
Enter pH Limit : 6.5pH
Use the and keys to set the pH limit. The allowable range is 0.0 to 14.0 pH.
Press to save the new value, or press to quit without saving the changes.
4. The control limits are now set to the required values.
2.2 Control Direction
The hydroCHEM is factory set to add nutrient when the Conductivity reading is lower than the
limit, and to add acid when the pH reading is higher than the limit. To change these settings…
1. Select the Limits menu ( →→ F3:Limits).
2. Select F2:Direction from the menu. The following screen will now be displayed…
Select Conductivity Direction
→→F1:Add when LOW F2:Add when HIGH
The arrow indicates the current selection.
Press to add nutrient when the Conductivity reading is lower than the limit.
Press to add freshwater when the Conductivity reading is higher than the limit.
3. The hydroCHEM confirms the selection and then goes on to select the pH Direction…
Select pH Direction
F1:Add when LOW →→F2:Add when HIGH
The arrow indicates the current selection.
Press to add alkali (eg. Soda Ash) when the pH reading is lower than the limit.
Press to add acid when the pH reading is higher than the limit.
4. The hydroCHEM confirms the selection before going back to the Limits menu.
8
2.3 Control Sensitivity
To stop the pumps being rapidly switched on and off, the hydroCHEM operates the pumps for a
preset band around the control limit. Examples to illustrate this are given at the end of this section.
To select the Control Sensitivity…
1. Select the Limits menu ( →→ F3:Limits).
2. Select F3:Sensitivity from the menu. The following screen will now be displayed…
Select Cond. Sensitivity
F1:Fine →→F2:Medium F3:Coarse
The arrow indicates the current selection.
Press to select Fine Sensitivity. The control band will be 0.1 mS/cm.
Press to select Medium Sensitivity. The control band will be 0.2 mS/cm.
Press to select Coarse Sensitivity. The control band will be 0.3 mS/cm.
3. The hydroCHEM confirms the selection and then goes on to select the pH Sensitivity…
Select pH Sensitivity
F1:Fine →→F2:Medium F3:Coarse
The arrow indicates the current selection.
Press to select Fine Sensitivity. The control band will be 0.1 pH.
Press to select Medium Sensitivity. The control band will be 0.2 pH.
Press to select Coarse Sensitivity. The control band will be 0.3 pH.
4. The hydroCHEM confirms the selection before going back to the Limits menu.
9
2.4 Control Limit Set-up examples
1. The following diagram illustrates the Conductivity control action of the hydroCHEM, when
the limit is set to 2.0 mS/cm, adding when low, with medium control sensitivity (0.2 mS/cm).
2. The following diagram illustrates the pH control action of the hydroCHEM, when the limit is
set to 6.5 pH, adding when high, with fine control sensitivity (0.1pH).
10
2.5 Alarms
An alarm function is available to provide an indication that Conductivity and/or pH have been
outside the limits by a set margin for a set period of time. This alarm is useful, as it can provide
forewarning of a potential system problems, such as empty tanks or faulty sensors.
To use the alarm function, the alarm margin on either side of the limit must first be set. A delay
time must then be set so that the alarm is not activated immediately. This allows for momentary
spikes outside the alarm margin. Once the alarm margin and delay times have been set, the alarm
function must be enabled. The following sections detail these procedures, and examples are
provided at the end.
2.5.1 Setting the Alarm Margins
1. Select the Alarms menu ( →→ F3:Limits →→ F4:Alarms).
2. Select F2:Set Alarm Margins from the menu. The current Conductivity alarm margin is
displayed. For example…
Enter COND Alarm Margin :0.30mS/cm
Low Alarm at 1.50, High Alarm 2.30mS/cm
Use the and keys to set the Conductivity alarm margin. The minimum alarm margin is
dependant on the Control Sensitivity setting, which can be 0.10 mS/cm (Fine), 0.20 mS/cm
(Medium) or 0.30 mS/cm (Coarse). The maximum alarm margin is 2.00 mS/cm.
The Low and High Alarm values displayed are calculated using the current Conductivity Limit
and Sensitivity settings.
As the or key is released, the display is updated with re-calculated Low and High Alarm
values.
Press to save the new value, or press to quit without saving the changes.
3. The current pH alarm margin is now displayed. For example…
Enter pH Alarm Margin : 0.3pH
Low Alarm at 6.2pH, High Alarm 7.0pH
Use the and keys to set the pH alarm margin. The minimum alarm margin is dependant
on the Control Sensitivity setting, which can be 0.1 pH (Fine), 0.2 pH (Medium) or 0.3 pH
(Coarse). The maximum alarm margin is 3.0 pH.
The Low and High Alarm values displayed are calculated using the current pH Limit and
Sensitivity settings.
As the or key is released, the display is updated with re-calculated Low and High Alarm
values.
Press to save the new value, or press to quit without saving the changes.
4. The alarm margins are now set to the required values.
11
2.5.2 Setting the Alarm Delay Times
1. Select the Alarms menu ( →→ F3:Limits →→ F4:Alarms).
2. Select F3:Set Alarm Delay Times from the menu. The current Conductivity alarm
delay time is displayed. For example…
Enter COND Alarm Delay Time : 10mins
Use the and keys to set the Conductivity alarm delay time. The allowable range is 5 to
60 minutes.
Press to save the new value, or press to quit without saving the changes.
3. The current pH alarm delay time is now displayed. For example…
Cond Alarm Delay Time : 10mins
Enter pH Alarm Delay Time : 10mins
Use the and keys to set the pH alarm delay time. The allowable range is 5 to 60 minutes.
Press to save the new value, or press to quit without saving the changes.
4. The alarm delay times are now set to the required values.
2.5.3 Enabling and Disabling the Alarm Function
To enable the alarm function…
1. Set the required Alarm Margins and Alarm Delay Times, as per sections 2.5.1 and 2.5.2.
2. Select the Alarms menu ( →→ F3:Limits →→ F4:Alarms).
3. Select F1:Enable from the menu.
The alarm function is now enabled. The alarm system is only functional when the
hydroCHEM is in Automatic Control mode (see section 3.3).
To disable the alarm function…
1. Select the Alarms menu ( →→ F3:Limits →→ F4:Alarms).
2. Select F1:Disable from the menu.
3. The alarm function is now disabled.
12
2.5.4 Procedure in event of Alarm function being tripped
When the alarm function has been tripped, the units for the relevant parameter flash and the
hydroCHEM beeps.
To check what has caused the alarm, press the key. To re-set the alarm function, press the
key.
Automatic control will continue even while the alarm is activated, as the hydroCHEM will
attempt to correct the alarm condition.
The condition that caused the alarm function to trip must be rectified to avoid it being tripped again.
This may involve one or more of the following…
•Check and re-calibrate the Conductivity and/or pH sensors to ensure the reading is actually
correct.
•Extend the ON time if the pump rate is not high enough to keep up with chemical demand for
the current ON time.
•Place the chemical addition point as close as possible to the take-up for the sample chamber.
•The Conductivity and/or pH levels in the system may have changed too rapidly for the dosing
pumps to keep up. If this was due to a singular event (eg. top up tank with fresh water), then the
alarm may be ignored. If this was due to normal operation and none of the above suggestions
have worked, larger capacity dosing pumps may be required. Contact your distributor or the
TPS factory.
2.5.5 External Alarm Siren
An external alarm siren is available for alarm indication (part no. 130101). This may be particularly
useful if the hydroCHEM is mounted inside a shed or pump room.
The external alarm siren simply plugs into the Pump Sensor / Alarm socket.
13
2.5.6 Alarm Set-up Examples
1. The following diagram illustrates the Conductivity alarm function of the hydroCHEM, with an
alarm margin of 0.3mS/cm and an alarm delay time of 5 minutes. The limit is set to 2.0mS/cm,
adding when low and with medium control sensitivity (0.2 mS/cm).
2. The following diagram illustrates the pH control action of the hydroCHEM, with an alarm
margin of 0.3pH and an alarm delay time of 5 minutes. The limit is set to 6.5 pH, adding when
high and with medium control sensitivity (0.2pH).
14
3. Control Set-up
The hydroCHEM control function must be set up correctly before attempting to use the
hydroCHEM for automatic control. Setting up the control function involves setting the ON and
OFF times for each pump. Conductivity and pH ON and OFF times can be set independently, to
allow for the different effects these have on the total system.
The ON time is the maximum amount of time the pump will operate continuously. For example, if
the Conductivity ON time is set to 5 minutes, the Conductivity pump will add A&B Nutrient for a
maximum of 5 minutes and then wait for the OFF time. Of course, if the Conductivity gets back
within the limit earlier, the pump will stop before the end of the 5 minutes.
The OFF time is the waiting time between ON cycles. Even if the Conductivity or pH go outside
their normal limits during the OFF time, the hydroCHEM will not activate the relevant pump until
the entire OFF time has elapsed.
In the examples shown in sections 3.1 and 3.2, the ON times are both set to 5 minutes and the OFF
times are set to 10 minutes. This means that the unit will dose for a maximum of 5 minutes, then
wait for 10 minutes. These ON and OFF times cycle repetitively. At all times, the Conductivity and
pH pumps will only operate when the readings are outside the limits.
Correct use of an ON and OFF cycle will avoid overdosing problems.
3.1 Setting up the Conductivity control function
1. Select the Control menu ( →→ F2:Control).
2. Select F3:Conductivity from the menu. The following screen is now displayed…
Enter ON Time : 5 minutes, 0 = Offline
Use the and keys to enter the ON time for the Conductivity pump (up to 30 minutes).
Enter Zero to take the Conductivity pump off line.
Press to save the new value, or press to quit without saving the changes.
3. The hydroCHEM then goes on to the OFF time entry…
ON Time : 5 minutes
Enter OFF Time : 10 minutes, 0 = Untimed
Use the and keys to enter the OFF time for the Conductivity pump (up to 30 minutes).
Enter Zero to make the Conductivity pump operate on demand whenever the reading is outside
the limit.
Press to save the new value, or press to quit without saving the changes.
4. The Conductivity control function is now set up and the hydroCHEM returns to the Control
menu.
15
3.2 Setting up the pH control function
5. Select the Control menu ( →→ F2:Control).
6. Select F4:pH from the menu. The following screen is now displayed…
Enter ON Time : 5 minutes, 0 = Offline
Use the and keys to enter the ON time for the pH pump (up to 30 minutes).
Enter Zero to take the pH pump off line.
Press to save the new value, or press to quit without saving the changes.
7. The hydroCHEM then goes on to the OFF time entry…
ON Time : 5 minutes
Enter OFF Time : 10 minutes, 0 = Untimed
Use the and keys enter the OFF time for the pH pump (up to 30 minutes).
Enter Zero to make the pH pump operate on demand whenever the reading is outside the limit.
Press to save the new value, or press to quit without saving the changes.
8. The pH control function is now set up and the hydroCHEM returns to the Control menu.
3.3 Selecting Automatic Control or Standby Modes
To enable the hydroCHEM to automatically control Conductivity and pH, Automatic mode must
be selected. The pumps will operate according to the ON and OFF times discussed in sections 3.1
and 3.2, when Conductivity and/or pH readings are outside the limits.
To disable automatic control (eg. when calibrating the unit), Standby mode must be selected.
To switch between Automatic and Standby modes…
1. Select the Control menu ( →→ F2:Control).
2. When the hydroCHEM is in Standby mode, select F1:Auto to switch to Automatic mode.
When the hydroCHEM is in Automatic mode, select F1:Standby to switch to Standby
mode.
NOTE
Automatic control is disabled when there is no flow in the sample chamber. The Conductivity, pH
and Temperature data is replaced by "NoFlo" when there is no flow.
16
4. Quick-Dose Function
The Quick-Dose function enables the operator to quickly add a measured dose of Nutrient A,
Nutrient B and/or pH adjustor, regardless of the Limits or Control set-up. This feature is particularly
useful to prime the pumps, or to trim up a fresh tank of water before commencing normal automatic
control.
To begin a Quick-Dose cycle…
1. Select the Control menu ( →→ F2:Control).
2. Select F2:Quick Dose from the menu.
3. The hydroCHEM now prompts you to enter the dosing time for the Nutrient A pump. The
default time is 5 minutes….
Enter Cond. A Quick Dose Time : 5 mins
Use the and keys to set the time for which the Nutrient A pump is to operate (from 0 to
10 minutes).
4. The hydroCHEM now prompts you to enter the dosing time for the Nutrient B pump. The
default time is 5 minutes. The Nutrient A pump time remains on the display, for your
reference…
Cond. A Quick Dose Time : 5 mins
Enter Cond. B Quick Dose Time : 5 mins
Use the and keys to set the time for which the Nutrient B pump is to operate (from 0 to
10 minutes).
5. The hydroCHEM now prompts you to enter the dosing time for the pH pump. The default time
is 5 minutes…
Enter pH Quick Dose Time : 5 mins
Use the and keys to set the time for which the pH pump is to operate (from 0 to 10
minutes).
6. The hydroCHEM now returns to the Control menu. To start the Quick-Dose cycle, the unit
must be returned to normal display mode. The display will count down the dosing time
individually for each pump.
NOTES
•To stop the Quick-Dose cycle, press the key. It is then necessary to repeat this
programming procedure to re-enable the function.
•The Quick-Dose function is enabled even when there is no flow through the sample chamber.
Before using this function, ensure that addition of Nutrient A, Nutrient B and/or pH adjustor
will not over-dose your system.
17
5. Flow Sensing
5.1 hydroCHEM-DS Flow Sensing
The hydroCHEM-DS uses the Conductivity reading to determine if there is an adequate flow of
nutrient solution through the sample chamber. See section 10.2 for details on how to adjust the
sample flow rate.
This feature has been provided so that the hydroCHEM-DS can be switched on at all times, and
automatic dosing only occurs when the pump which feeds the sample chamber is operating. No
separate flow sensing or timer cycle is therefore needed for the hydroCHEM-DS to dose at the
required times.
The following conditions occur when there is little or no flow of nutrient through the sample
chamber…
•The data is replaced by "NoFlo" on the hydroCHEM display.
•Automatic control is disabled. The Nutrient and pH pumps will not operate until adequate flow
is restored.
•Quick-Dose is still operational. Ensure that the quick dose cycle will not cause the system to be
over-dosed.
•The Conductivity, pH and Temperature being sent to the RS232 port is replaced with spaces
(see section 16.6).
5.1.1 Flow Sensing Troubleshooting
Symptom Possible Causes Suggested Remedy
"NoFlo"message does not
appear, even when the
Conductivity sensor is dry and
in air
1. Sensor has a build-up of
salts or algae between
wires.
2. Sensor is faulty.
Clean probe as per section
25.2.2.
Return sensor to factory for
repair or replacement.
"NoFlo" message appears
even when the Conductivity
sensor is in solution.
1. Conductivity of solution is
below 500 µS/cm (245 ppm
TDS).
2. Sensor is faulty.
The flow sensing function
only operates if the
Conductivity is above 500
µS/cm (245 ppM TDS).
An optional pump detector is
available to solve this
problem. Please contact the
factory or your distributor.
Return sensor to factory for
repair or replacement.
18
5.2 hydroCHEM Flow Sensing
The hydroCHEM is supplied with a pump sensor. Plug the pump sensor into the “Optional
In/Out” socket on the hydroCHEM.
This sensor detects whether or not the feeding or recirculating pump is operating. The ideal location
for mounting pump sensor is nearest the pump motor, as per the diagram below. After mounting the
sensor, switch the pump on, and check that the "NoFlo" indication is replaced by the
Conductivity/TDS, pH and Temperature data on the hydroCHEM display.
This feature has been provided so that the hydroCHEM can be switched on at all times, and
automatic dosing only occurs when the feeding or recirculating pump is on. No separate flow
sensing or timer cycle is therefore needed for the hydroCHEM to dose at the required times.
The following conditions occur when the pump sensor detects that the pump is not operating…
•The data is replaced by "NoFlo" on the hydroCHEM display.
•Automatic control is disabled. The Nutrient and pH control outputs will not be activated unless
the feeding or recirculating pump is operating.
•Quick-Dose is still operational. Ensure that the quick dose cycle will not cause the system to be
over-dosed.
•The Conductivity/TDS, pH and Temperature data being sent to the RS232 port is replaced with
spaces (see section 16.6).
5.2.1 Flow Sensing Troubleshooting
Symptom Possible Causes Suggested Remedy
"NoFlo"message does not
appear, even when the feeding
or recirculating pump is OFF.
Pump Sensor is faulty. Return sensor to factory for
repair or replacement.
"NoFlo" message appears
even when the feeding or
recirculating pump is
operating.
1. Pump Sensor not mounted
in optimum position on
pump housing.
2. Pump Sensor is faulty.
Try mounting the sensor in
alternative positions on the
pump. The best position is
close to the pump motor.
Return sensor to factory for
repair or replacement.
19
6. Temperature Calibration
The temperature readout must be calibrated or manually set before attempting Conductivity or pH
calibration. The decimal point is replaced by a “ ∗∗ ” if the reading is not calibrated.
6.1 Temperature Calibration Procedure
1. Ensure that the hydroCHEM is in Standby mode (see section 3.3).
2. Plug the Conductivity/Temperature sensor into the Cond/Temp socket.
3. Place the sensor into a beaker of room temperature water alongside a good quality mercury
thermometer. Stir the sensor and the thermometer gently to ensure an even temperature
throughout the beaker.
4. Select Temperature Calibration ( →→ F1:Calibrate →→ F3:Temperature).
The Temperature Calibration screen is now displayed. For example…
Enter Actual Temperature : 25.0 24*0Oc
Temperature Calibration Menu Quits
The cursor is at the new temperature value you will be setting.
The current reading from the Temperature sensor is displayed on the far right of the top line.
5. When the reading from the Temperature sensor has stabilised, use the and keys to enter
the same temperature as measured by the mercury thermometer.
6. Press the key to calibrate the temperature readout.
Alternatively, press the key to abort temperature calibration.
6.2 Temperature Calibration Notes
1. The hydroCHEM has an allowable Offset range of –10.0 to +10.0 OC. If calibration fails due to
the Offset being outside these limits, then please consult the Troubleshooting guide (section
24.4) for possible remedies.
2. Temperature calibration information is retained in memory when the hydroCHEM is switched
off, even when the power supply is removed. This information can be recalled later using the
GLP function (see section 14).
3. Temperature does not need to be re-calibrated unless the Conductivity/Temperature sensor is
replaced or the meter is initialised.
6.3 Temperature Calibration Messages
1. If a temperature calibration has been successfully performed, the hydroCHEM will display the
following message and the offset of the sensor. For example…
Temperature Calibration OK
0.1OC Offset
2. If a temperature calibration has failed, the hydroCHEM will display the following message
and the failed offset value of the sensor. For example…
Temperature Calibration Failed
11.0OC Offset
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