Tunable Dedektörler (FPI)

Tunable Detectors FPI Detectors

Here you can find all tunable detectors from InfraTec

Due to their spectral properties and robustness, pyroelectric detectors have proven themselves for many years in numerous applications in gas analysis, flame detection and spectroscopy. They enable the tuning of the optical filter over a defined spectral range by simply adjusting the control voltage. Instead of mounting filters to inspect specific areas of interest as is conventionally common, the detector with tunable Fabry-Pérot filters (FPF) can be used to monitor a broad spectral region continuously.

• Four spectral ranges available
• Spectral resolution (λ / Δλ) up to 60
• Electrostatic actuator for tuning the wavelength
• Active compensation of position and temperature changes
• Current mode
• Thermally compensated
• Evaluation kit available

Advant­ages of Fabry-Pérot Inter­fer­o­meter (FPI Detectors)

• High flexibility in terms of the measurement substances
• Application chemometric methods for multi-component analysis
• Measurement of known compositions with overlapping bands
• Identification of unknown substances
• Cost-effective, robust and miniaturized solution

Areas of Applic­a­tion
The method of infrared spectroscopy, based on a physical sensor principle, is an established method in the field to determine concentrations and compositions very selectively and with long-term stability. The applications are so diverse that only a few important examples can be listed. While it plays a particularly important role in gas analysis, this method is also used for liquid and solid analysis.

Process Meas­ure­ment – Analysis of Liquids in Chem­ical Processes
Fluid analysis in chemical manufacturing processes is an essential component for the optimization of product quality and safety. FPI detectors have the advantage, besides their high flexibility in terms of substances to be measured, that in their design, they are significantly cheaper, more robust and more compact than other large and very expensive process spectrometers or other complex measuring techniques such as ATR probes in combination with NDIR sensors.

Energy Tech­no­logy – Determ­in­a­tion of the Energy Content of Natural Gas or Biogas
The determination of the energy content, for billing purposes or for improving the energy efficiency of combustion processes, is very time-consuming and costly with previous instruments such as gas chromatography. These processes were also hardly economical when used in smaller plants. The resulting increase in demand for cheaper, faster and more precise sensors has been met with the FPI detector due to its design and measurement properties.

Medical Tech­no­logy – Monit­oring/​Dosage of Anes­thetic Gases
Medical Technology – Monitoring/Dosage of Anesthetic Gases In order to monitor and ensure the safe dosage of anesthetics, up to five gases, mainly in the wavelength range 8 … 11 µm, in addition to nitrous oxide and carbon dioxide must be measured simultaneously. Due to the number of gas components to be measured, spectrometric measurement and evaluation is the best method. Due to the very compact design, there is a significant miniaturization advantage when compared to conventional methods based on fixed filters.

Further Applic­a­tions for the Use of FPI-Detectors

• In safety technology for the detection of toxic or hazardous material or explosive gases
• In environmental and climate research, for the measurement of emissions, for the identification of plastics in waste sorting, leak detection in pipes, the composition of the atmosphere, etc.
• For the measurement on surfaces to detect contaminants, to ensure the complete coating of reflective material, to test the thickness of coatings or ensure the complete wetting of lubricants

Product Range FPI Detectors

Different types with first order filters and wide tuning ranges are currently available. They span nearly the whole mid and long wave infrared range of about 3 … 11 μm. Other ranges or customized designs may be possible on request.

Devices with integrated ASIC can be operated in a control loop – in this type designation they are characterized by the letter “C”. Position feedback of the reflector plates is given by capacitance measurement. This means the filter can be stabilized against external acceleration forces. Temperature drifts are automatically compensated by closed loop operation as well.

*(400 ºC, 10 Hz, 1 Hz, 25 ºC) [10E+8cmHz1/2/W]

Setup of FPI Detectors

The Fabry-Pérot filters are integrated into TO8 housings together with a LiTaO3-based pyroelectric detector. The latter is a state of the art thermally compensated current-mode type with an integrated op-amp. The element size of 2 × 2 mm2 matches the size of the filter aperture. The order sorting filter is integrated in the cap.

Calibration data are stored in an EEPROM. An integrated ASIC offers feedback on the position of the moving mirror plates. The closed loop control greatly improves center wavelength (CWL) stability under the influence of changing gravity, e. g. by rotating the detectors inside a portable device.

FPI Brochure
Get further information about pyroelectric detectors with spectrometer functionality from InfraTec.

Down­load FPI brochure