Wavetek Meterman LP10A Operator's Manual page 14

Minimum Detectable Pulse Width
Frequency
Minimum Pulse width
Pulse amplitude + 3 V
Input Impedance
Pulse Indicator Flash Time
Audible tone at pulse rate
Operating Temperature
Storage Temperature
1 kHz 1 to 20 kHz
100 ns 50 ns
1 MΩ
500 mS
no
0 °C to 50 °C at 80 % R.H.
-20 °C to 65 °C at 75 % R.H.
10
20 kHz to 20 MHz
30ns
1 MΩ
500 mS
yes