Translate the given Spanish text to English

Let me give you an example: A method for converting a series of m-bit information words to a modulated signal is described.
The answer to this example can be: Se describe un método para convertir una serie de palabras de informacion de bits m a una señal modulada.
Here is why: The translation is fluent, formal, and accurate

OK. solve this:
The apparatus measures substance concentration by detecting radiation in the far infrared range emitted by the body using an infrared detected in combination with a set of adequate filters.
Answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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El aparato mide concentración de sustancia mediante detectar radiación en el rango infrarrojo lejano emitida por el cuerpo usando un infrarrojo detectada en combinación un conjunto de filtros adecuados.