Spatial Resolution and Minimum Length to Be Heated

The incident laser pulse width and sampling interval are major factors to decide the specification of the temperature distribution measured by DTS.
The key factors to evaluate the DTS performance other than the temperature resolution, the spatial resolution, and the minimum measurement length, are mainly decided by laser pulse width and the sampling interval are defined as follows.

- Sampling Interval

Suitable sampling interval is decided in consideration of spatial resolution and the allowable minimum sampling interval setting is 0.5m. The temperature measuring data by DTS is output and displayed in each interval.

- Spatial Resolution

The spatial resolution of DTS is defined as the distance between 10% and 90% points on its response to a step in temperature versus distance function, therefore adjacent sample points are not truly independent.

-Minimum Measurement Length

Supposing the simplest of hotspot profiles to be square, the hot spot is effectively a rise in temperature closely followed by a fall in temperature, or two step changes in temperature. The spatial resolution of the DTS determines the minimum length of fiber required to be heated to achieve> 95% accuracy. The corresponding relationship is: Min. length of fiber to be heated = 2×Spatial Resolution + 1×Sampling Interval