Trouble Shooting Tips

CoBex Recorders, Inc.

The following sections were generated from FAQ's (frequently asked questions):

How do I select the proper chart for my recorder ?

How do I change the range of the recorder ?

What is the purpose of the three button touch pad ?

What does a flashing green LED light indicate ?

Why does the pen move to the warmest temperature on the chart
when my process temperature dips below the coldest temperature ?

The recorder is losing time (around 1 to 2 hours a week)

The pen moves in the wrong direction as the temperature increases/decreases

 


Selecting the proper chart for the recorder ...

The recorders manufactured by CoBex are programmed (at the factory) with up to eight different temperature (or voltage/current) input ranges. These ranges correspond to standard charts that have been available for temperature recorders for over 30 years. The recorder may be programmed with only one temperature range which means that there is only one chart that can be used with the recorder. Attempting to operate the recorder using the wrong chart will result in inaccurate readings. If you need to operate the recorder with a chart other than the one intended to be used, you must return the recorder to CoBex to have the recorder re-programmed in order to use a different chart. If you are not sure of the type of chart to use, contact CoBex. They will be able to tell you which charts are valid for your recorder by the serial number. The serial number can be found in one of three places: on the front of the chart plate, on the back of the chart plate or on the back of the recorder enclosure.

Recorders with multiple ranges ...

It is very important to verify that the recorder is configured properly for the chart that is being used on the recorder. You must manually configure the recorder for the chart that you wish to use on the recorder. This is done by using the three button touch pad located on the front of the recorder's chart plate and is explained later in this section.

To determine if your recorder is programmed with more than one temperature range, look on the front of the chart plate (where the chart paper is located) for a range sticker that lists the multiple ranges of the recorder. This will also be a list of the only charts that can be used with the recorder. The following is an example of the type of information that will be found on a range sticker:

1.) 0 to +100ºC (7 Day)
2.) -40 to +60ºC (7 Day)
3.) 0 to +60ºC (7 Day)
4.) -100 to +38ºC Rev (7 Day)

From the above information, we know that this recorder has been programmed with four (4) ranges. The information 7 Day refers to the rotation speed of the chart (usually 7 Day or 24 Hour). The Rev (in range #4) specifies that a reverse reading chart must be used for this range. Normal charts have their lowest value located at the center of the chart and reverse reading charts have their lowest value located at the outside edge of the chart. When the recorder is configured for a reverse reading chart, the pen will move to the left as the temperature decreases. When the recorder is configured for a normal chart, the pen will move to the right as the temperature decreases.

If this is a six inch recorder, then the following is a list of the ONLY charts that can be used with this particular recorder (the size of the recorder refers to the nominal size of the chart paper that is used on the recorder):

C7-100-0-6 (for range #1)
C7-60-40-6 (for range #2)
C7-60-0-6 (for range #3)
C7-100+38-6 (for range #4)

If you try to use any other chart on this particular recorder, you will not get accurate readings. For a list of available charts, refer to the "Chart Number Selection" table.

Change the range of the recorder ...

To select/verify the temperature (or voltage/current) range of the recorder, follow these instructions:

STEP 1:
While the recorder is operating normally (recording temperature), press the change chart button (#3) and release it when the pen begins to move off of the chart.

STEP 2:
Once all of the pens have moved off of the chart and have stopped, press and hold button #1 for approximately eight (8) seconds and then release the button.

 

Three Button Touch Pad w/Green Indicating Light

STEP 3:
The green LED light (located below the three button touch pad) will begin flashing to indicate the range that is currently selected for the recorder. The figure to the left shows that the recorder is currently in range #4. This is determined by counting the number of times that the green LED light flashes. There are four quick flashes of the green LED light followed by a longer pause. After the long pause, the green LED light begins flashing four times again and repeats the cycle.

 

STEP 4:
Press and release button #1 to increment to the next range. Press and release button #2 to decrement to the previous range. The green LED light will flash to indicate the current range that is selected.

 

STEP 5:
To permanently save the current range that is selected, press and release the change chart button (#3) and the pen(s) will return to the chart and begin recording temperature.


The three button touch pad ...

The three button touch pad has multiple functions depending on the mode that the recorder is operating in. Note: never use a rigid object (such as the tip of a pen) to depress the buttons of the three button touch pad. This will permanently damage the button.

When the recorder is operating normally (recording temperature), button #1 (left arrow) and button #2 (right arrow) are used to calibrate the temperature reading of the recorder. These buttons must be held for several seconds before any calibration will take place. This is done so that the calibration of the recorder is not changed accidently by someone inadvertently pressing either button #1 or #2. The change chart button (#3) is ONLY used to move the pen(s) OFF and ON the chart in order to change the chart paper easily.

When the pen(s) have moved completely OFF of the chart (after pressing the change chart button), then button #1 and button #2 are used to configure the recorder for one of the temperature (or voltage/current) ranges that are programmed into the recorder. Refer to the section "Change the range of the recorder" for information concerning this topic.

When the chart change button is pressed in order to bring the pen(s) back onto the chart, each pen will briefly stop at the outermost graduation of the chart. If the pen(s) are not calibrated to this position of the chart, you will have several seconds to adjust the pen's position using button #1 (left arrow) and button #2 (right arrow). The calibration of the pen(s) to the outermost graduation of the chart should be checked each time the chart is changed and each time the fiber tip pen(s) are replaced.


Flashing green LED light ...

The green LED light flashing steadily usually indicates that either the battery (used for the battery back-up feature of the recorder) is LOW and needs to be replaced OR there has been a loss of main power to the recorder and it is running totally off of the battery.

If the green LED light flashes several times followed by a longer pause, this may indicate that you have inadvertently entered into the range change mode of the recorder. If this is the case, refer to the section "Change the range of the recorder" to see if you have executed the steps required to enter into this mode.

The green LED light will be solid green (not flashing) when the recorder is operating normally.


Pen moves to warmest temperature of chart and remains there...

The recorder is programmed to sense and record a specific temperature range. When the temperature that is being measured goes outside of this range, the recorder enters into an out of range condition. When this happens, the recorder positions the pen at the highest value on the chart to indicate that there may be a problem. Therefore, it is a good idea not to record a temperature that is too close to the coldest temperature on the chart because you may see the pen sweeping back and forth as the temperature that is being recorded goes in and out of range.

This may also be an indication that the recorder is not configured properly for the chart that is being used on the recorder. Refer to the section "Recorders with multiple ranges" for information concerning the configuration of the recorder.

Finally, it could be an indication that there is a problem with the probe. Check for loose wire connections or cuts in the probe wires.


The Recorder Loses 1 to 2 Hours a Week ...

The recorder is not actually losing time, there is some "play" in the motor that rotates the chart. This "play" is caused by the backlash of the gears in the chart motor's gearbox. When placing a new chart on the recorder, make sure that the chart knob is tightened fully clockwise. Do not try to "line-up" the pen with the time on the chart by backing-up the chart counter-clockwise after the chart knob has been tightened. Otherwise, the chart motor has to take-up the "play" in the gears before the chart will begin to rotate. (Note: There is approximately 1 to 2 hours of "play" in the gears of the chart motor.)


The pen moves in the wrong direction as the temperature increases/decreases ...

This will occur when the chart that is being used on the recorder does not match the range that is configured for the recorder. Refer to the section "Selecting the proper chart for the recorder" and "Recorders with multiple ranges".


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