True-rms Digital Multimeter 
  How to Make Measurements 
31 
Table 7. Functions and Trigger Levels for Frequency Measurements 
Function Range 
Approximate 
Trigger Level 
Typical Application 
 
6 V, 60 V, 
600 V, 1000 V 
±5 % of scale  Most signals.  
 
600 mV  ±30 mV  High-frequency 5 V logic signals. (The dc-coupling of the  function can 
attenuate high-frequency logic signals, reducing their amplitude enough to 
interfere with triggering.) 
 
600 mV  40 mV  Refer to the measurement guidelines given before this table. 
V 
6 V   1.7 V  5 V logic signals (TTL).  
V 
60 V  4 V  Automotive switching signals. 
V 
600 V  40 V  Refer to the measurement guidelines given before this table. 
V 
1000 V  100 V   
 
Frequency counter characteristics are not available or specified for these functions. 
 
 All ranges  ±5 % of scale  AC current signals. 
μA 
600 μA, 6000 μA 30 μA , 300 μA  Refer to the measurement guidelines given before this table. 
 
60 mA, 400 mA  3.0 mA , 30 mA   
A  6 A, 10 A  0.30 A, 3.0 A