World's First Eight Channel Pyroelectric Detector in TO8 Housing
Pyroelectric detectors are ideally suited for gas analysis. Until now, it only gets complicated if many gases should be measured. There are often simply too few measuring channels for this purpose. The LRM-278 from InfraTec offers exactly the right solution for this. This detector combines eight measuring channels in a TO8 housing with a diameter of 15.2 millimeters. As a result, the number of gases that can be measured with a single detector of this size doubles in one fell swoop.
Double Space Savings
When looking at the design of the single supply detector, two details become clear, which make a significant contribution towards ensuring that such a powerful solution fits into such a small space. The first detail is the central window built directly in the cap, which all other models of the series of miniaturised multi channel detectors have, too. The correspondingly large aperture of 8.5 × 8.5 mm2 means that the LRM-278 has a very large field of view (FOV). This gives rise to its outstanding signal-to-noise ratio.

The second detail is concealed inside the detector. There, on special chip carriers, the sensitive pyroelectric sensors, the compensation elements as well as the 2 × 2 mm2 filters are positioned directly on top of each other. Due to this stack design, there is sufficient space for all other components.
Das Raumwunder – der LRM-278 - PYROMID®‐ Achtkanaldetektor von InfraTec
Further Features of LRM-278
- Central window built directly in the cap
- FOV: 80°
- Pyroelectric chips: 1.4 x 1.4 mm2 per channel
- Filters: 2 x 2 mm2
- Detectivity: 4.5E+08 cm√Hz/W
- Temperature sensor integrated in the detector
- Single supply OpAmp for current mode
- Thermal compensation available
- Completely hermetically sealed on request

Temperature Sensor Directly in the Detector
The frames with sensitive elements and filters are arranged in a square each with three times three fields. With a total of eight channels, one field thus remains free – the one in the middle. At this position there is a temperature sensor. With gas sensors, the temperature is usually measured as well. Until now, this has not been possible directly in the detector, however. Measuring the temperature inside the detector, for example, provides the option of compensating the typical temperature drift of the filters very accurately by means of a calibration.
In addition to the measurement accuracy, there are also the benefits resulting from the current mode of the LRM-278. This means that it impresses particularly by its fast displaying of signal changes and dynamic response behaviour. The resulting high signal voltage simplifies the circuit design and allows the detector to become more resilient against disturbances. The higher signal levels support the easy integration of the detector into measuring modules.
Possible Applications
- Complex tasks within the gas analysis
- Analysis of medical and technical gases
- Measurement of emissions
- Safety technology
LRM Series: Miniaturised Multi Channel Detectors
LRM detectors by InfraTec offer an extremely wide FOV in combination with a compact design and attractive pricing. Their central window in the cap provides reliable protection against environmental influences. Optionally soldered to the housing it enables complete hermetic sealing. The channel filters are placed inside the detectors close to the pyroelectric elements. The reduced distance and the central window integrated into the detector caps ensure a wide FOV.

LRM Detectors at a Glance
- Assortment of 2-, 4- and 8-channel detectors
- Operation in voltage mode or current mode
- Extremely wide FOV provides powerful performance
- TO46, TO39 and TO8 housings available
- Robust central window for protection against penetrating moisture
- Thermal compensation available
InfraTec – Specialist for Infrared Sensors
InfraTec has been developing, producing and selling pyroelectric infrared detectors for more than 25 years. Primarily single and multi channel infrared detectors are offered. One of the latest innovations in this group is a series of miniaturized multi channel detectors – the LRM series. A group of infrared sensors with electrically tunable MOEMS-based filters is also suitable for solving the most demanding measurement tasks. Users apply InfraTec products in areas such as industrial and medical gas analysis, fire and flame detection, spectroscopy and non-contact temperature measurement. The company also offers a comprehensive range of services. This includes consulting in detector design, support in choosing the right IR filters and simulation of IR absorption spectra. In order to coordinate activities in the economically most important markets of Europe, North America and Asia, InfraTec has established several international subsidiaries. In addition, operates within an international distribution network.