PVS-31 Image Intensifier Tube Specs
Image Intensifier: Gen2+ Multi-Alkali Photocathode (White Phosphor)
Offers balanced sensitivity and resolution, better low-light performance than Gen1, and a more natural image with white phosphor. Good for hunting, surveillance, and navigation, it's a solid choice.
FOM (Figure of merit): Min 1600
A metric used to assess the overall performance of an image intensifier tube.
FOM = Resolution (lp/mm) × Signal-to-Noise Ratio (SNR).
In this case 64lp/mm x 25 = 1600
Resolution Ratio: 64lp/mm (or better)
Refers to the resolution, indicating the system's ability to distinguish 64 line pairs per millimeter. Higher values like this one mean finer detail and better image quality, essential for identifying objects or navigating in low light.
Signal to noise ratio: 25 (or better)
The Signal-to-Noise Ratio (SNR) is a critical metric for night vision devices as it affects image clarity, especially in low-light conditions. A higher SNR usually means a clearer, crisper image with less "noise" or graininess. An SNR of 25 for a Gen 2+ device is on par with many Gen 3 systems.
Photocathode sensitivity: 850-950μA/lm
The photocathode is a component that absorbs photons (light) and emits electrons in response, which are then amplified to produce an image. A more sensitive photocathode can detect lower light levels and produce a clearer image. Greater optical sensitivity allows the device to produce clearer images in darker environments.
Luminance Gain: 10,000
Refers to the amount by which the device amplifies available light to produce a visible image. A luminance gain of 10,000 means that the device amplifies the light 10,000 times.
Equivalent Background Illumination: 0.2
A measure used in night vision devices to quantify the amount of light that would produce the same level of noise or image interference as the actual background noise in the device. A lower EBI value indicates less electronic noise, and therefore a clearer, cleaner image. An EBI of 0.2 is good, especially for Gen 2 and Gen 3 devices.