Siemens SITRANS TO500
12 January 2017
The fiber-optic sensor – measuring what used to be impossible.
The extremely thin multipoint measuring system
Measured values are transmitted through the extremely thin sensor measuring lance. The diameter of the sensor measuring lance is independent of the number of measuring points.
To optimize throughout, lifetime and yield
Recognizing temperature profiles and detailed understand- ing of the process are great challenges to plant operators. The fiber-optic based SITRANS TO500 multipoint measuring system enables you to determine a large number of tem- perature measuring points along a single sensor fiber and read out a temperature profile in a matter of seconds. In this way, you can, for example, localize points of overheat- ing quickly and precisely to avoid or counteract damage in good time.
Typical application areas for the SITRANS TO500 are, for example, temperature measurements in:
• tube and tube-bundle reactors
• capillary and microreactors
• distillation
• rectifications
Function of the SITRANS TO500
Do you want to install a very large number of measuring points in the smallest possible space with a low thermal mass? The fiber optic weighs only a few grams, and its diameter of < 2 mm enables the SITRANS TO500 to make measurements in very narrow protective tubes, leaving a larger volume in the vessel for the the reaction.
The response time of the sensors is also reduced because of the low thermal mass of the fiber optic lance.
The SITRANS TO500 multipoint measuring system compris- es two components:
• transmitter (reading unit)
• sensor measuring lances (with up to 48 temperature measuring points)
A continuously tunable laser generates light in the SI- TRANS TO500 transmitter with a wavelength between 1500 and 1600 nm, which is output to the sensor measuring lances. The transmitter evaluates the reflected light compo- nent. Fiber Bragg Gratings (FBG) are inscribed at defined points on the sensor measuring lances, that reflect a de- fined wavelength. The wavelength reflected by the grating changes as a function of temperature and so indicates the temperature at the relevant measuring point. A gas cell with a fixed absorption line serves as a reference in the SITRANS TO500, against which the determined wavelength is continuously calibrated.
The transmitter sends the measured values via a Profibus DP interface to the control system for evaluation.
