The light table I mentioned
earlier is a bit of a dinosaur. But it’s a reliable dinosaur. It sits in the corner and is forgotten about 99.9% of the time. You don’t need another light table, you just need to keep (unearth?) the one you have tucked away somewhere.
Semi-log paper is consumable. It’s getting harder and harder to find, too.
You may ask, “Why the hell would anyone need semi-log paper? Doesn’t everyone have a spreadsheet/graphing program?”
There are some problems with computer-only semi-log graphing:
1. When you graph something in excel, the points are immutable unless you actually track down the point in the spreadsheet and adjust it. In order to see patterns in the data (for example, what slope you need to use to analyze the time-drawdown data for an aquifer test), it’s often easier to adjust points so that you can figure out what actually happened.
2. If you’re in the field and you’re trying to decide if you have enough data to continue a drawdown test, it’s often easiest to do a quick sketch of your manual measurements rather than reconnecting multiple transducers to a laptop or hand-held device and fiddling with the data so you can put everything together.
3. Excel is becoming a black box. Does a student actually understand what a logarithmic scale is? If they’re using a published graph of data, can they compare their results and see what they have? In both my instructing gig and my TA days in grad school, I’ve found that students are stymied by creating simple graphs by hand. If you can’t put points on a graph, how can you interpret the graphs that excel made for you?
Maybe I’m old and too suspicious of computer gadgetry. But I can plot something up and figure out trends to bolster an argument in 30 seconds using my trusty semi-log paper.