Scientific Equipment Jan Arrigo May 23, 2014 News from the Top of the World, Schools 2 Comments Scientists use many different types of equipment to help with their research. The equipment helps by either gathering or testing samples. On this research cruise there are large and small types. CTD The CTD is the largest and it gets submerged into the water. It measures the Conductivity (how salty the water is) and Temperature at different Depths in the ocean. The outer part of the CTD has a circle of Niskin bottles called a rosette surrounding it. The rosette collects water samples. Van Veen Grab The Van Veen Grab is a giant claw-like mechanism. A crane lowers it from a cable to the bottom of the ocean where it takes up a big scoop of mud and rocks. The sample is brought back to the surface and dumped into a tray. The scientist carefully looks through the sample to see what organisms are in the mud. He/she takes them back to the lab for further study. LOKI The LOKI is a camera set at the bottom of a plankton net. The camera takes photos of the plankton as they pass out of the net. The Bongo net is a set of two nets set inside two round frames. One net collects small zooplankton, and the other larger zooplankton. Bongo Nets 2 Responses Shawn Trieschmann May 28, 2014 Hi, I am a student at Falmouth Academy and find it so interresting about how many different things you test and find when you are out on the ship. The CTD is very fascinating to me, how it is able to measure how salty the water it. I also really like the Van Veen Grab, i was wondering where did the name come from? -Shawn T Reply Ben Harden June 9, 2014 Hi Shawn, thanks for the comment. The CTD is the workhorse of the physical oceanographer. They use it to map all the currents in a region my moving the ship progressively along a line and take profiles that they can they join together into a cross section. It measures salinity indirectly by measuring the conductivity of the water. A voltage is applied between two probes and the conductivity between them is related to how salty the water is. We have to calibrate it though by taking a few water samples in the bottles surrounding the CTD sensors and directly measuring the salinity of these. This makes sure that the continuous measurements of conductivity relate accurately to salinity. Reply Leave a Reply to Ben Harden Cancel Reply Your email address will not be published. Name* Email* Website Comment Notify me of follow-up comments by email. Notify me of new posts by email.