Check and double-check
Gerhard Behrens |
| When students finish something in my class, one of the first things I say to them is, “Check your work.” I expect them to make sure their name is on the paper, the first letter in a sentence is a capital, and a period or question mark ends every sentence. I point out sentences that need better spelling, I tell them if an answer is not complete, or I circle math problems that aren’t correct. Their job is to check those errors and correct them. |
Two to three tests are done on each sample of water, then recorded by hand. |
| In the lab, the scientists and technicians are always checking that their work is done correctly. |
| When water samples are taken at different depths, a CTD monitor is attached to the sample cage (rosette) to measure saltiness, temperature, and the depth. Sometimes, our ship uses two CTD monitors to make sure the readings are correct. A computer program reads both monitors and tells the scientists the difference between one monitor and the other so they can always check for accuracy. |
The nutrients tests are recorded in a computer and on a graph. |
The salinometer is another machine that measures how salty the water is. Every water sample is measured 2 times to make sure the amount of salt is correct. If those measurements are not almost exactly the same, then a third measurement is taken to check for accuracy. After every 30 samples, a bottle of special salt water is run through the machine to test that the machine is working correctly. |
| Measurements from the CTD are always checked with measurements from the salinometer to check for accuracy of the CTD. |
| When testing for nutrients in the water, the lab technician runs the water samples through a very complicated set of tubes and machines. The information is recorded and saved on a computer. The information is also displayed on a graph. With these two ways of recording, the techs and scientists can check for accuracy. |
| To test for freon, water samples go into a fancy machine and measurements show up on a computer. The lab tech also writes down the measurements, as he understands them. Back on shore in the lab, a second person will review the computer data and write down the measurements as they see them. The information from all three records is compared, to check for accuracy, before the data is considered correct. John, the technician, brought a bottle of special freon on the ship to test that his machine is working correctly. |
The freon measurements go into a computer’s memory and are recorded by hand in a notebook. |
| The list of checking goes on and on. The mooring team checks their equipment to make sure it works. A team of people works 24 hours a day to check that the equipment attached to the bottom of the ship is on and working. |
| It may not be an exciting part of the work of a scientist, but it is very important to make sure the collected information is correct. Checking and double-checking is part of the job. |
