How does the JBL pH-Control recognise a “bad“ sensor?
The pH sensor transmits a voltage to the measuring device, which convert the voltage into the pH value.
This voltage does NOT remain constant throughout the service life of the sensor! It needs to be calibrated regularly. The device is thus informed about the age-related change in voltage and can display reliable values again.
The calibration takes place at pH 7 and pH 4.
At pH 7 a new sensor transmits a voltage of 0 mV (+/- a few mV) to the measuring device. The more the voltage at pH 7 deviates from 0, the older the sensor is. The deviation can occur at + or -. At a deviation of more than +40 or -40 mV the device rejects the sensor.
The error message OFFSET appears.
NOTE: The same error message appears if you accidentally begin to calibrate at 4!!
At pH 4 the sensor transmits a voltage of about +186 mV (when 7 is at 0 mV). This means that between the single steps (4-5; 5-6 and 6-7) there is in each case a difference of about 62 mV. The smaller this difference, the older the sensor. With differences below 30 mV the device rejects the sensor.
The error message DELTAV appears.
NOTE: The same error message also appears, when you accidentally calibrate twice at 7!!
IMPORTANT: Rejected sensors can often be brought “back into operation” if you soak them intensively in storage solutions (for several days)!
What deviations during the calibration are usual and how are they connected to the temperature?
It is difficult to give a precise answer without information about the sensor, particularly the age of the sensor. Good sensors have deviations in the range from 0.02 to 0.05 pH levels when calibrating.
The input voltage differs for each sensor, as each sensor has its own individual properties. For the majority of our sensors, it is between -30 and +30 mV at pH 7.
Both input voltages (pH 7 and pH 4) are important when assessing the quality of a sensor. The greater the difference between these two values, the better the sensor and the precision of the measurement and control. The differences should be over 140-150 mV.
The temperature sensor should always be used during calibration. The pH level varies according to temperature, so that it is always best to measure the pH level with temperature compensation. The deviation is between 20 and 30 °C, 0.17 pH levels, and the relationship is nonlinear.
Why does the controller permanently indicate a too high/low pH value? And why doesn’t the calibration work although the sensor is new?
The cause can probably be fixed quite easily. The protective cap of the pH sensor needs to be removed before insertion into the aquarium / before the calibration, to carry out control/calibration correctly. The protective cap serves as storage and “reactivation” of the sensor with the storage liquid. It has to be removed for use inside the aquarium and during the calibration because no water from outside can pass through. If the controller still displays an error, even after the removal of the protective cap, please read the FAQ with the several error messages in detail.
What does the message OFFSET mean?
The message OFFSET indicates: The sensor voltage at pH 7.00 is outside the limit value, the sensor is too old, the cable is defective, no sensor is connected or the calibration has been performed with buffer 4 solution.
Remedy: Check the sensor cable for any signs of damage and repeat the calibration. Take care to use the buffer solution correctly. If this does not work, replace the sensor and calibrate again.
How often does the JBL pH Control Touch need to be calibrated?
In the menu you have the chance to choose the interval before the next calibration reminder. The following calibration intervals are available:
However it is highly recommended not to select the 60 days setting, since each pH sensor wears continuously and the measured values become subject to change. Thus the more often you carry out a calibration the more reliable are the measurement results.
We would like to integrate the JBL Proflora pH Control Touch in a customised cover of our own design. For the construction we need the dimensions of the control unit (WxHxD), the required connection area for the cables and hoses and possibly information about whether it has a wall or surface mounting (blind frame) option.
The JBL ProFlora pH Control Touch has the following dimensions: W x H x D: 89 mm x 67 mm x 25 mm. Including the connections the height is 78 mm.
You also need to allow about 4-5 cm for the connection area under the control unit to ensure an easy installation.
Although it is not possible to mount the controller directly to the wall, it can be mounted on a top-hat rail, which can then be fixed to a wall. The above mentioned depth includes the top-hat rail.
Why does the pH value jump in the display of the JBL ProFlora pH Control Touch?
If the pH value is subject to greater fluctuation, this is an indication of interference from another electronic device. Ballasts in light bars, for instance, create an electromagnetic field if they are not shielded against interference. This can disturb the sensitive sensor. When you unplug the power plug from the outlet the pH value should suddenly stabilise. You can carry this process out with every electrical device in the aquarium to find the source of interference.
By using separated power-carrying cables further disturbances can be avoided. Separating electrical circuits may also prove to be a good idea. The JBL pH Control Touch units are manufactured and tested in accordance with EMC directives and do not interfere with other technical items. Thus the JBL pH Control Touch does not expose wearers of pacemakers to any danger.
If another technical item disturbs your pH control, then it has not been electromagnetically shielded in accordance with this technical standard.
The display for the temperature at the JBL ProFlora pH Control Touch indicates N/A. What does this mean?
A display of N/A means that the pH controller is not receiving any input value. This may be due to the following:
1) There is no contact in the plug, perhaps caused by a slightly corrosive coating. Please check the contact points of the plug.
2) The temperature sensor is not connected.
Note: The JBL pH Control Touch can also be operated without a temperature sensor. In this case, the controller adjusts to a water temperature of 25 °C.
Do I need a night shut-off when I use the JBL Proflora pH Control Touch?
You need a separate soleniod valve (JBL ProFlora v002) to control the CO2 supply. A further night shut-off for CO2 systems, controlled by a pH control unit is not necessary, because the systems do not, or very rarely, switch on (outgassing CO2 above the water surface) the CO2 supply if there is no CO2 consumption. That’s why the control devices don’t need a timer.