The “manual” that you link to provides no useful information at all. And I can find no other information about your meter.
I will guess that the terminals marked with the pulse symbol, 8-9 & 10 - 9, are the pulse connections.
Have you connected a voltmeter to those terminals, and can you see a voltage pulse at all? I think it is not very likely that the meter will give out a voltage, but you must check this first.
If you cannot see a voltage, I will guess (again a guess) that inside the meter, these terminals connect to an opto-transistor. Try connecting a red LED, a resistor of about 3.9 kΩ and a 9 V battery all in series across 8 - 9 or 10 - 9, with the battery positive to 8 or 10. If you see a dim flash, then my guess was correct. If not, try with the connections to terminals reversed.
This may help you.. It’s the same manufacturer but a different meter.
Post when you have some more information.
