PYS Series Single-element Pyrodetectors PIR

Responsivity 3.5 kV/W Typ.; Max. Noise 50 µVpp; Spec. Detectivity 17 x 107cm*√Hz/W; FoV (Horizontal/Vertical) 77°/77°, 135°/120°; Operating Voltage 2-10 VDC

Single-element pyroelectric detectors (PIR) are often applied for temperature and gas measuring applications in one-channel or dual-channel variants, which is then one output per element. Excelitas offers its PYS Series of single-element pyrodetectors as thermally compensated devices.

The principle of gas monitor application is called NDIR. NDIR requires detectors with narrow-band optical filters. Excelitas provides a range of suited filter windows for those gases which show an absorption band in the IR spectral range.

Excelitas’ PYS 3198 TC GX (replacement to LHi 807) is a single-channel, parallel format temperature-compensated elements PIR detector based on lithium-tantalate (Li-Ta). In the design for PYS 3198 TC, a single sensing element is placed in the center of the detector. For thermal compensation an additional element, (which is blinded from radiation), is connected in parallel.

The TO-5 metal housing is equipped with an optical filter window. For gas measurement applications with Excelitas’ single-element pyrodetectors, typically the spectral range is narrowed to match the gas absorption in the IR range. As such the window is acting as a narrow-band optical filter.

Almost like two detectors in one housing, the PYS 3428 (replacement to LHi 814) dual-channel, single-element pyrodetector includes two single-elements which are each thermally compensated by an additional blinded element sitting aside. Each output is optically linked to an individual optical window within the TO-5 metal housing. For each window, a variety of narrow-band optical filters are available to meet a range of specific sensing requirements.

Each element has its own individual output signals, thus the name dual-channel. Since the PYS 3428 Pyrodetector has been specifically designed for gas measuring applications, it comes with narrow-band optical filter windows. Typically, one window is used as reference, for which Excelitas provides the filter version G20 as the reference window.

The PYS 3928 TC digital dual-channel pyrodetector includes two single elements, both thermally compensated by an additional blinded element sitting aside. Each element is digitized and available as a 2x16-bit output at the digital link pin. Each element is optically linked to an individual optical window within the TO-5 metal housing. For each window, a selection of narrow-band optical filters is available to meet your specific detection requirements.

As part of Excelitas’ DigiPyro series, this design offers the output of both sensing elements as a 2x16-bitstream of the direct link. With this 16-bit resolution, smaller noise values are given per digit. Since the PYS 3928 TC DigiPyro PIR has been designed especially for gas measuring applications, it comes with narrow-band optical filter windows. Typically, one window is used as reference, for which Excelitas provides the filter version G20. For the second window, various suited narrow-band filter windows are available.

Applications: Non-dispersive Infrared (NDIR) Gas Sensing; CO2 Channel; CO2 vs. Reference Channel