My brain is struggling with some basic stuff here. I’ve got this little area in my report which looks for a Hammer Correction Factor.
At present, I’ve got the Hammer Correction in two locations in my library.
One here, in Rig Type
The other is in a Hammer Correction Factor area. It shows more detail, and allows a history to be maintained.
We only use the correction factor at one location in the database (Sample), but we’ve had to use it with each sample, not each borehole. It comes from “Libtbl!hammer correction factor”
Here’s my report Lookup function. It doesn’t seem to like it. I’ve tried several ideas, but I can’t get it to work the way I want.
For now, I’d just love to get my silly HCF to show up. What am I doing wrong?
Secondly, I was discussing some things with a colleague. In the future, there may be long investigations which are over the span of a couple of correction factors. With that, we’d have to have a way to tie in a couple different factors in the same project. Right now, we have the factor tied to a single rig. Any reference to that rig only has a single HCR. I almost feel like we’d need to add a duplicate rig with a different factor in this case. Do you have any alternate ideas on this?
Without getting into your specific functions, my approach was to include the hammer efficiency (and all other rig/hammer info) directly in the point table of the project rather than in a library table with a lookup. This allows you to directly access the efficiency for each borehole. The reasons for this are as follows:
1. We work with many different drillers with different rigs. It us far easier to input the efficiency directly in the field based on the rig and actual equipment that is there than to constantly maintain a library table. As you know sometimes equipment and tools are shared from rig to rig
2. As you note, if the rig gets recalibrated halfway through a project, this approach associates the efficiency with the hole that was drilled by the rig rather than the rig itself
3. The efficiency is permanently attached to the hole data so that if the project is opened with a different or outdated library, the efficiency will still be correct. This avoids logs printed at 2 different times having different N60.
4 if you have 2 rigs with the same designation the lookup may be erroneous. Further, if the rig designation is not entered exactly as it appears in the table it will fail.
Yes this means that at input time you need to input more information and it is sometimes repetative. We handle this in the field using pre populated dropdown lists to speed the input of rig info. The possibility of input errors are there, ie one day the field logger may select a 140 lb. Hammer and the next day he may select a 300 lb hammer by mistake
As to why your lookup expression is not working. It seems you have the return field and the lookup reference expression reversed in the expression.