Yang Huaijiang

Performance Test of Steel Tube Enclosed Thermistors in Air Temperature Measurements

The performances of two steel tube enclosed precision thermistors are tested in a well controlled air environment to determine if the thermistors have enough accuracy for ±0.01°C levels of air temperature gradient measurement. Three Fluke’s 5641 and three 5610 thermistors were tested for 24 hours in Fluke’s 7008 calibration bath in the first step. In the second step, two of the 5641s were airproofed in a temperature well controlled tube, the performances of these two thermistors in steady state and transient state air temperature environments were tested for 8 hours separately. The results illustrate that, when steel tube enclosed precision thermistors are used in air temperature measurement, there are unstable departures from each other with a maximum 8.8 m°C in constant air medium and 27 m°C in temperature changing air medium. The transient-time errors are too large to show the true amounts of temperature changes for air temperature measurement.

Target characteristic extraction algorithm based on block structure variables

In image processing system, the target recognition is very crucial. An optimized algorithm based on the definition of block is presented. In this algorithm, two structure variables are self-defined to calculate the areas and centroids of targets. The labeling conflicts are resolved by tracking and correcting, which means that if there is a conflict, trace the neighbored blocks and correct the labels of them. Finally, the characteristics of blocks, which have the same label, are accumulated. This method has outstanding advantages in saving memory, compared with Pixel labeling algorithm and Run-length code algorithm. The new algorithm is simple and the results of target characteristics are easy to be analyzed and handled in the following processes.