UNI-T UT151A, Operating Manual

     Notice
1)  Refer to Notice 1, 2 and 3 in the Direct Current Measurement.

1.  Insert the black pen into COM hole and red pen into 

Ù

 hole.

2.  Place the functional switch at 

Ù

 range. Connect the test pen to the resistance to be test in 

     parallel.

     Notice
1)  If the resistance to be tested is more than the maximum value of the range selected, over-
     range 

1

 will be shown. You shall select higher range. For resistance more than 1M

Ù

 and 

     above, the reading can become stable after several seconds; this is normal for high 
     resistance reading.
2)  When input is not made, such as open-circuit conditions, the instrument shows 

1

.

3)  When you check the impendence of internal circuits, power supply to the circuit to be tested 
     must be cut off and capacitor charges must be totally discharged.
4)  There are 10 digits at 200 M

Ù

 short-circuit which shall be subtracted from the reading. For 

     example, 101.0 is shown in measurement of 100 M

Ù

 resistance and the 10 digits shall be 

     subtracted.

3-5 Resistance measurement

3-6 Capacitance testing

     Prior to connection to the capacitance to be tested, note that time for zero reset is needed for 
each change of range. Existing drift reading cannot influence the testing precision.

      Notice
1)  Although protection to the capacitance shift is set by the instrument, testing shall still be 
     carried out after capacitor discharge to avoid damage to the instrument or causing measuring 
     error.
2)  In measuring capacitance, insert the capacitor into the capacitance testing seat.
3)  In measuring large capacitance, it will take a certain time period to get stable reading.
4)  Unit: 1pF=10   

µ

F, 1nF=10   

µ

F

-6

-3

3-7 Frequency measurement

1. Insert the red pen into the Hz hole and the black pen into COM hole.
2. Place the functional switch at kHz range; connect the test pen to the frequency source. You 
    can directly read the frequency from the display.

3-8 Temperature measurement

1. In measuring the temperature, insert the cold end (free end) of thermocouple sensor into the 
    temperature test seat and at the same time note the polarity. Place the working end 
    (temperature measuring end) on or inside the object to be tested. You read the temperature 
    directly from the display which is expressed in 

 or 

.

3-9 Diode testing and buzzer continuity testing

1. Insert the black pen into COM hole and red pen into V

Ù

 hole (polarity of red pen 

+

); 

    place the function switch at  shift; connect the pen to the diode to be tested. The reading is 
    the approximate value of forward voltage of diode.
2. Connect the pen to both ends of circuit to be tested. If the resistance between both ends is 
    lower than about 10

 Ù

, the built-in buzzer rings.