2M Detector circuit overlay

2M Detector circuit overlay

2M Thermopile Detector

2M Thermopile Detector

A thin film-based single element thermopile detector that offers the world's highest sensitivity in a TO-5 package. Dare to compare. Low noise voltage of 12.8nV/√Hz.

Excellent for gas analysis, fire detection and non-contact temperature measurement.

Extremely high output with best signal-to-noise performance with a time constant of 85ms when encapsulated with Argon gas.


  1. See Standard Windows and Filters (PDF) for list of optical filter options
  2. Internal 30kΩ 5% NTC chip thermistor provides ambient package temperature measurement. See DC-4005 section of Thermistor Options (PDF).
  3. Order this unit encapsulated with Xenon and this becomes a super-high output detector with very low noise.
  4. See Thermopile Configuration Table for more options.

For more detailed information see the following datasheets; 2M (PDF) without Thermistor, 2M (PDF) with Thermistor

Specifications apply at 23°C with KBr Window and Argon encapsulating gas.

Parameter Min Typical Max Symbol Units Comments
Active Area size   2 x 2   AA mm Hot junction size, per element.
Element Area   4   A mm2  
Number of Junctions   48       Per element.
Number of Channels   1       Per detector package.
Output Voltage 200 250 300 Vs μV DC,  H=330μW/cm2 (3)
Signal-to-Noise Ratio 12,739 19,531 33,333 SNR √Hz DC, SNR=Vs/Vn
Responsivity 15.2 18.9 22.7 V/W DC, =Vs/HA  (2)
Resistance 5 10 15 R Detector element
Temperature Coefficient of   -.36     %/°C Best linear fit, 0° to 85°C (1)
Temperature Coefficient of  R   -.2     %/°C Best fit, 0° to 85°C (1)
Noise Voltage 9.9 12.8 15.7 Vn nV/√Hz Vn2=4kTR
Noise Equivalent Power .44 .68 1.03 NEP nW/√Hz DC,  NEP= VnHA/Vs (2)
Detectivity 1.9 3.0 5.0 D* 108√Hz/W DC,  D*=Vs/ VnH√A  (2)
Time Constant   85   Τ ms Chopped, -3dB point (1)
Field of View   38°/95°   FOV Degrees See Assembly Drawings for FOV Description.
Package Type   TO-5       Standard package hole size:Ø.150"
Operating Temperature -50   100 Ta °C  

General Specifications: 
Flat spectral response from 100nm to > 100µm.  Linear signal output from 10-6 to 0.1W/cm2
Maximum incident radiance 0.1W/cm2 , damage threshold ≥ .5W/cm2

(1) Parameter is not 100% tested. 90% of all units meet these specifications.
(2) A is detector area in cm2.
(3)Test Conditions: 500K Blackbody source; Detector active surface 10cm from 0.6513cm Diameter Blackbody Aperture.

Product Finder

Product Comparison Guide

The Gold Standard

The Collaboration Station

Contact Us