If a template is set up to use 'Follow-on Mode', the Unit per Page Expression will determine the units per page for the 'follow-on' pages rather than the first page. The first page will be output with the same scale (but a different depth per page if the Plot Area has a different height).
For example, here we have set this template up to output 5 Units per Page. We see the 2nd (Follow-On) Page has 5 m per page, whereas the first page (with a bigger header and smaller Plot Area) only shows ~4.4 m per page.
This is opposite of the behavior in gINT where the ‘Depth Units Page 1’ settings determine the depth units for the first page and subsequent pages use the same scale (but a different depth per page if the body heights are different).
In OpenGround, you may want similar behavior to easily set the first page depth, which can be done using a Unit per Page Expression (and optionally Options), as described below…
The general Units per Page expression you will need to use is:
Expression to Determine First Page Depth * Follow-On Plot Area / First Page Plot Area
In this example, we will use a Location Option to determine the fist page depth, with a default of 10 m if no Option is entered:
if(isblank([LocationOptions.UnitsPerPage]),10,[LocationOptions.UnitsPerPage])
The Follow-On Plot Area is 208 mm. The First Page Plot Area is 184 mm.
So, our final Units per Page expression is:
if(isblank([LocationOptions.UnitsPerPage]),10,[LocationOptions.UnitsPerPage]) * 208 / 184
You would need to adjust the expression for the Plot Areas within your template design.
We can then test how this works… We’ve entered a Units Per Page Option of 5 m. We generate our log report and see that now the first page shows 5 m depth. And the second page has the same scale, but shows ~5.7 m depth due to the larger Plot Area.
Additional Notes
If the ‘Units per Page’ expression does not return a value, such as if an Option is not entered, it will use the default Units per Page defined in the template or Report Profile when generating Quick Logs or Log Reports. In this case, the units per page will revert to the standard behavior, and the Units Per Page settings will apply to the 'follow-on' pages. To prevent this in the example above, we’ve included the default value of 10 m within the expression, which will be used if no Option is entered.
There are many potential variations to how your Options and Units per Page expression can be set up to achieve the behavior you would like. Please see the How to Vary the Units Per Page (Depth) on a Log article for further documentation and examples.