RayTek 54301 - Manual (Page 49)

Operation
6.4.3 Valley Hold
The output signal follows the object temperature until a minimum is
found. Once the hold time is exceeded the output signal, tracks and
output the actual object temperature and the algorithm will start over
again. The range for the hold time is 0.1 to 998.9 s.
Temp
output temperature
object temperature
hold time
hold time
Time
Figure 27: Valley Hold
A defined hold time of 999 s (symbol “∞” in the display) will put the
device into continuous valley detection mode.
A low level input (GND) at external input FTC3 will promptly
interrupt the hold time and will start the minimum detection again.
MID 41