Pyrocam III
HR
User Guide
Document No. 50361-001
Rev E
7/18/2017
Page 20
that will reduce the effective rate to a value that falls just within a rate supported in pulse
mode 2.
For example, a pulse rate of 150Hz will be divided by 2, yielding a capture rate of 75Hz. A
pulse rate of 1000Hz will be divided by 9, yielding a rate of 111Hz. Note that this does not
mean that the Pyrocam will output data frames at a rate of 75 or 111Hz. The actual frame
rate output from the Pyrocam is limited by equipment bandwidths that are not accurately
predictable.
Figure 3.4 : Mode 3, High Speed,
𝒇
𝒎𝒂𝒙
< 𝒇
𝒕𝒓𝒊𝒈
< 𝟏𝟎𝟎𝟎𝑯𝒛
𝑓
𝑚𝑎𝑥
= (8.705𝑚𝑠 + 𝑇
𝐸
)
−1
Use Mode 2, Periodic timing.
𝑓
𝑝𝑠𝑟
=
𝑓
𝑝𝑢𝑙
⌈
𝑓
𝑝𝑢𝑙
𝑓
𝑚𝑎𝑥
⁄
⌉
Example: Laser pulse rate is 350Hz, Exposure 50us, Delay 0us
Solution:
𝑓
𝑝𝑠𝑟
=
350
⌈350 114.22
⁄
⌉
=
350
4
= 87.5𝐻𝑧
3.4
Chopped (CW) Operation
The Pyrocam chopped models contain an internal chopper for use with CW lasers or to do
thermal imaging when fitted with a specialized lens. The operation of the chopper is managed
by the camera’s firmware and no external trigger is required when in chopped mode. The chop
rate can be reduced to increase responsivity, but with some loss in response linearity.
