Back to Inclination Measurements

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Extended Options

So, the first time we launch the inclination panel, we see no view options selected, like this:

Open

The first available user option is ‘Display Inclination Curve’, which gives us this view:

Open

This option adds a 2nd line to the graph and a new scale on the right side for reading this curve against. This thin line is a plot of the actual data points that have been collected by the camera during the test and is not the shape of the pipe. This is displayed by the thick blue line.

Notice that the scale on the right has its zero point somewhere near the middle of the vertical axis, because as we already know, sometimes the camera is pointing up (positive inclination data points) and sometimes it is pointing down (negative inclination data points), but on balance, there will be a majority or an average of either negative or positive which will tell us that the pipe is falling in the expected direction.

See in this example that most (not all) of this line is below zero, so the camera was generally going downhill, which is what we would expect from a downstream inspection. has we tested exactly the same pipe from the other end, the graph would roughly be flipped about its horizontal axis (turned upside down), because the camera would have generally been going uphill, but the shape of the thick blue line would not change, because we are always sticking to the intuitive convention of always presenting the curve in the downstream direction.

When the inclination curve crosses the zero vertical axis point, then the camera is dead level, and if you look carefully at where this happens, the thick blue line is flat at this point. Where the thin curve is positive, the thick line is going up and where it is negative the tick blue line is going down.

The next user option is ‘Smooth Inclination’:

This user option smooths out the curve to make it look ‘nicer’. It also adds the translated text ‘(Smoothed)’ to the chart title because this option could be used to make the pipe look better than it really is, and customers might be unhappy to see this, particularly in Sweden.

The 3rd user option is 'Show Gridlines:

This turns on the graph paper background for the chart which can be useful for taking measurements against the horizontal and vertical scales of the two graphs.

Of course, the user can turn on any combination of these three options or all three if they wish:

The ‘Save Graph’ button allows the user to save the chart with its current display in a number of user friendly graphics file formats for use in external applications.

The ‘Show Data’ button gives us a pop up with all of the data points for this test. This is very useful for diagnosing problems, and can also be used to delete individual points:

The 3 columns displayed here are:

1. The measurement point number.

2. The distance measurement for this point in metres or feet.

3. The attitude measurement for this point in %

It is clear to see from this data if the test was done with the camera going forwards or backwards. In a forwards test, the distance will increase as the counter increases, and in a backwards test it will decrease as the counter increases.

The multi-select tool with the small green tick in the lower left corner is used to activate the checkboxes against the measurement points where the user can delete selected points. This is useful when there are some bad points in the data, almost always within the metre closest to the CCTV truck because of the effect of the cable tugging the back of the camera unit upwards into the manhole as has been described previously.

The Print button simply create a single sheet printout of the current chart with the user options that are currently selected in the inclination panel. More about printing later.

This example shows us a ‘Delta Altitude’ of -0.09 m and a ‘Measured Inc.’ of -0.41 %

These are calculated from the received data points and are good values that describe a ‘happy’ drain that is flowing the right way.