Abstract Details
| Name: Varun Kumar Affiliation: IIA, Bengaluru Conference ID: ASI2019_403 Title : Testing the Performance of Inductive Edge Sensor Against Environmental Changes. Authors and Co-Authors : Varun Kumar, Padmakar Parihar, Suraj Kumar, Sai Prabhat, Arjun Manoharan, Maria Joseph and Merin George Abstract Type : Oral Abstract Category : Instrumentation and Techniques Abstract : Edge sensor plays a very critical role in any segmented mirror telescope (SMT). It measures any relative displacements between mirror segments and provides a feedback signal to the primary mirror control system. The edge sensors are designed to have a very high spatial resolution (few nanometers), large range, ability to sense multiple dimensions simultaneously and should have minimal effect of environmental changes. As a part of National Large Optical Telescope (NLOT) project, we have been working to develop an inductive edge sensor. Our continuous effort from the past three years has resulted in a working inductive edge sensor which is very close to meet the performance requirement of any mid-size seeing limited SMT. These edge sensors once installed at the telescope, are exposed to the open environment, and any change in the environmental parameters like temperature, humidity, may affect the sensor performance. Therefore, one of the critical requirement for any edge sensor is that sensor reading should be almost invariant during intra-night as well as well seasonal changes. Additionally, a requirement which makes task further difficult is that sensor should not also get affected by any dust settle on its active surface. From initial laboratory testing, we noticed that our sensor has high-temperature sensitivity as well as some signature of the presence of hysteresis. This behavior of the sensor is of great concern as sensor output must remain stable for a week time or so. We have extensively studied the temperature behavior both by simulation and experimentation and came up with a solution. Here we report the efforts made in diagnosing and solving the temperature problem as well results of the very extensive environmental testing of our edge sensor. |