The Metascopes


The U.S. Carbine Caliber .30

- Infrared -

Sniperscopes & Equipment
















Infrared
Background
&
Overview

Sniperscope
&
Snooperscope

Model T120/M1

Sniperscope

Model M2
(Early & Late)

Sniperscope
Set No. 1, 20k volts

Model M3

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Infrared-Sensitive Phosphors at Work

The Metascopes

The term "Metascope" generally applies to any scope that views infrared light as visible light. During WWII this term was used for the devices utilizing infrared sensitive phosphors. The term expanded to include other IR imaging devices after WWII.

The metascopes of WWII paired an infrared image-sensitive phosphor with a simple optical system. These devices generally lacked the clarity of a telescope but were capable of viewing the presence of infrared light without the size and weight of a telescope and accompanying power source.

A phosphor coated panel suspended inside the metascope was exposed to an excitation source which in turn activated the ability of the phosphor to convert near-infrared light to visible light. The most common excitation source was a small incandescent light bulb. Excitation sources varied with the design of the infrared sensitive phosphor. One phosphor used ultraviolet light. Another used radioactive radium.

Between early 1942 and the end of the war, the research team at the Institute of Optics, University of Rochester designed and built eleven different metascope models. Six of these were accepted for quantity production by the Army and Navy. With the rapid pace of research and development, half of these were obsolete by the time the contractor was ready to start production. [2]

The "Type A" metascope was the first developed by the NDRC and in conjunction with the Navy.

The Navy's first field tests of the Type A involved signal communications between ships and American forces on the shore during the invasion of North Africa November 8-10, 1942 [1]. The tests revealed the production model required further attention. Production was halted before the contract was completed pending a redesign.

The pace and progress of research overtook the usefulness of the Type A metascope with the introduction of an improved phosphor before production problems could be worked out. It was recalled and replaced by the Type H-AM metascope (below).

Type A

Infrared Metascope


     Use:   Recognition, Signals, IR Detection   
     Phosphor Excitation Source:   Incandescent Bulbs (2)    
     Mount:   Hand held   
     Dimensions:   6" long x 3.5" wide x 3.5" high (approx.)   
     Weight:   1.8 lbs   

Contracts [2]

BranchContract #QuantityManufacturerStart DateEnd DateAmount
U.S. NavyOEMsr-1100*10.000**Samson United Corp.
Rochester, NY
1942early 1943unknown

* Both the Type A and Type B were manufactured under the same contract.
** Production suspended then cancelled before the contract was completed. It's not known how many were produced.

Type B

Infrared Metascope

     Use:   Recognition, Signals, IR Detection   
     Phosphor Excitation Source:   Incandescent Bulbs (2)    
     Mount:   Hand held and Ship   
     Dimensions:   6" long x 5.5" wide x 8" high (approx.)   
     Weight:   4.6 lbs   

Contracts [2]

BranchContract #QuantityManufacturerStart DateEnd DateAmount
U.S. NavyOEMsr-1100*5000Eastman Kodak
Rochester, NY
1943early 1944unknown

* Both the Type A and Type B were manufactured under the same contract.

While efforts to perfect the Type A metascope were under way the Type B metascope was developed at the NDRC at the request of the U.S. Navy. The Type B featured an aperture twice the size of the Type A with 2x magnification. Initially intended as an inline viewing system that would increase its detection distance the design was changed to a folding mirror system to reduce its bulk and weight. This reduced its detection distance to that of the Type A metascope.

Two Rotating Phosphor Panels (P)
Mounted at 45 degrees

Type US/F

Infrared Metascope

     Use:   Recognition, Signals, IR Detection   
     Phosphor Excitation Source:

Radium

   
     Mount:   Hand held   
     Dimensions:   3.31" long x 2.75" wide x 3.5" high   
     Weight:   0.85 lbs   

Contracts [3]

BranchContract #QuantityManufacturerStart DateEnd DateAmount
U.S. Army
Corp of Engineers
W30-082-ENG(MSP)-4327 Electronic Laboratories
Indianapolis, IN
1/458/45$3,681,000
U.S. Army
Corp of Engineers
W30-082-ENG(MSP)-4524 Samson United Corp.
Rochester, NY
1/457/45$3,375,000
    55,000       

The Type F metascope was the first of two successful and mass-produced near-infrared viewing devices. The combination of a new phosphor and optical system it employed gave the Type F high sensitivity and good image quality with a size and weight never before achieved.

Sealed inside was a small disk of radioactive radium on gold foil mounted on a lightweight swinging arm. Tilting the instrument exposed the phosphor to radium alpha particles making it sensitive to IR light. The unit was sealed to prevent exposure to radium's radioactive alpha and beta particles.

The Type US/F Metascope was tested concurrently to the Type C-1 Infrared Telescope by the U.S. Army Infantry Board at Ft. Benning, GA. The tests and conclusions appear in Infantry Board Report #1595A dated 17 Oct 1944. The Infantry Board recommended the Type U.S./F metascope be adopted for use by infantry.

A ten-page manual was included as Appendix B in TM 5-9340 Snooperscope & Sniperscope dated September 1944.

! WARNING !
This device contains radium which is radioactive

The Type F metascope cannot be refurbished and cannot be made operable. DO NOT open the device, attempt to repair it or attempt to remove the radium. The lifespan of the phosphor has long since ended rendering the device inoperable. With a half-life of 1600 years, the radium is still radioactive. As radium deteriorates it generates radioactive gamma rays that penetrate the exterior of the device.

The level of gamma radiation within 1 foot of the device can be hazardous to your long-term health. Radiation exposure is accumulative and stays with us throughout our lifetime with the potential of causing bone cancer. Keep your distance and limit exposure time. For additional information:

Center for Disease Control (CDC)


The U.S. Type F as manufactured by Samson United Corp. was slightly different than those manufactured
by Electronic Laboratories. Both met the specifications, operated the same and performed the same.

Single Phosphor Panel
with Swing Arm

  (A) Storage Position, Radium arm locked
(B) Button releases Radium arm exposing Phosphor to Radium
(C) Turn unit upside down, push button to lock Radium arm
(D) Turn unit rightside up, lift lid and view
 

Type US/AM

Infrared Metascope

Navy NAN R-1400

     Use:   Recognition, Signals, IR Detection   
     Phosphor Excitation Source:

Radium

   
     Mount:   Hand held   
     Dimensions:   7" long x 2.5" wide x 2.5" high   
     Weight:   1.5 lbs   

Contracts [3]

BranchContract #QuantityManufacturerStart DateEnd DateAmount
U.S. NavyNOBS 2041820,000*The Lewyt Corp.
Brooklyn, NY
2/4510/45$1,331,000

*Serial numbers observed for the US/AM under contract NOBS 20418 started at 01 and have exceeded 47,000.
It appears the quantity of the initial contract was increased during production.

The Type AM metascope was developed almost concurrent to the Type F. It was the second of the two consistently successful near-infrared viewing devices. It was an inline viewing version of the Type F. It used a small disk of radioactive radium mounted on a lightweight swinging arm. The device was sealed to prevent exposure to the radioactive alpha and beta particles of the radium. The Type AM included an accessory for mounting two side by side for use as binoculars.

! WARNING !
This device contains radium which is radioactive

The Type AM metascope cannot be refurbished and cannot be made operable. DO NOT open the device, attempt to repair it or attempt to remove the radium. The lifespan of the phosphor has long since ended rendering the device inoperable. With a half-life of 1600 years, the radium is still radioactive. As radium deteriorates it generates radioactive gamma rays that penetrate the exterior of the device.

The level of gamma radiation within 1 foot of the device can be hazardous to your long-term health. Radiation exposure is accumulative and stays with us throughout our lifetime with the potential of causing bone cancer. Keep your distance and limit exposure time. For additional information:

Center for Disease Control (CDC)

Single Phosphor Panel
with Swing Arm

References:

[1] "Infrared Signal Systems", Military Communications: From Ancient Times to the 21st Century, Christian H. Sterling, Editor, p.229-230, 2008
[2] Image Forming Infrared; Summary Technical Report of Division 16, National Defense Research Committee, 1946
[3] Alphabetic Listing, Major War Supply Contracts, Cumulative, June 1940 through September 1945, Industrial Statistics Division, Civilian Production Administration, 1946

Also see:
[a] Science in World War II Series; Applied Physics: Electronics, Optics, Metallurgy by the National Defense Research Committee, 1948
[b] Catalog of Naval Electronic Equipment, Supplement 1, January 1948

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Model T120/M1

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