The U.S. Carbine Caliber .30 |
 |
- Infrared -Sniperscopes & Equipment |
The U.S. Carbine Caliber .30 |
|
- Infrared -Sniperscopes & Equipment |
|
|
|
|
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.
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 AM metascope (below).
** Production suspended then canceled before the contract was completed. Unknown how many were produced.
 The Type A had two incandescent lamps (lower left and lower right) and two phosphor disks. One phosphor disc could be charged by a lamp while the other was being used by rotating the knob left or right.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
 | Type BInfrared Metascope |
| Use: | Recognition, Signals, IR Detection | ||||
| Phosphor Excitation Source: | Incandescent Bulb (1) | ||||
| Mount: | Hand held and Ship | ||||
| Dimensions: | 6" long x 5.5" wide x 8" high | ||||
| Weight: | 4.6 lbs |
Contracts | ||||||
| Branch | Contract # | Quantity | Manufacturer | Start Date | End Date | Amount |
| U.S. Navy | OEMsr-1100* [2] | 5000 | Eastman Kodak Rochester, NY | 1943 | early 1944 | unknown |
|
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.
|
|
Early production Type B Metascopes had two battery compartments that were sealed when the battery cap was
|
|
|
 | Type US/FInfrared 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 | ||||||
| Branch | Contract # | Quantity | Manufacturer | Start Date | End Date | Amount |
| U.S. Army Corp of Engineers | W44-009-ENG-120 [3] | Samson United Corp. Rochester, NY | 2/44 | 8/44 | $103,000 | |
| U.S. Army Corp of Engineers | W30-082-ENG(MSP)-4327 [3] | Electronic Laboratories Indianapolis, IN | 1/45 | 8/45 | $3,681,000 | |
| 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. Instructions for use are also included in FM 21-75 Combat Training of the Individual Soldier and Patrolling dated October 1950 and updated June 1957. |
| ! WARNING ! | |
|
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:
| ||
Single Phosphor Panel | ||
|
(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 | ||
The U.S. Type F as manufactured by Electronic Laboratories was slightly different than those manufactured
by Samson United Corporation. Both met the specifications, operated the same and performed the same.
 | |
| Left: | Electronic Laboratories Type F Metascope, rotary switch for charging & use |
| Right: | Samson United Type F Metascope, push button switch for charging & use |
|
|
|
A new more sensitive phosphor prompted the redesign of the Type A Metascope, designated the Type A1. This device used the optics of the Type A with the body of a Type A prototype. The scopes were vacuum sealed. This scope required about 4 hours prep time before it was ready for use. A charging plug was attached to terminals located on the rear of the main body for 2-3 minutes. The plug was removed then the scope was sealed within it's case for 4 hours, during which time the phosphor was excited.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
 | Type US/AMInfrared MetascopeNavy 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 | ||||||
| Branch | Contract # | Quantity | Manufacturer | Start Date | End Date | Amount |
| U.S. Navy | NOBS 20418 [3] | 20,000* | The Lewyt Corp. Brooklyn, NY | 2/45 | 10/45 | $1,331,000 |
| 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 ! | |
|
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:
| ||
CAUTION: DO NOT attempt to remove the red lens or open the unit. Doing so risks exposure to radioactive alpha
| |||||
|
References:
[1] "Infrared Signal Systems", Military Communications: From Ancient Times to the 21st Century, Christian H. Sterling, Editor, p.229-230, 2008
Also see:
Should you have questions, assistance is available on our Discussion Forum.
The Discussion Forum also serves as a reference desk for the more advanced material that could easily overwhelm a website and is often subject to opinions that may vary |
|
|
© Copyright 2012- The Carbine Collectors Club. All Rights Reserved.
