UNI-T
UT139A/B/C OPERATING MANUAL
VIII. Knobs and Keys for Range selection
Range Location
Function
AC or DC voltage measurement
a
Resistance measurement
■H-
Measurement of diode PN junction voltage
•»«
Measurement of circuit on-off
Capacitance measurement
Hz
Frequency measurement
%
Duty ratio masurement
t o
Temperature measurement
iu& mASs lOASi
AC/DC current measurement
60AS* A
AC/DC current clamp measurement
NCV
Non-contact AC voltage sensing
OFF
Switch off internal electric power
Button:
RANGE button: it can be used for selecting auto/manual range. After pressing, it will switch one gear of switch,
when reading the highest gear, jump to the lowest gear range and in turn. When the time of pressing button is
^ 2 s or switching a range, you'll exit the manual range mode. (Only applicable for V ^ / n / I ^ )
MAX/MIN button:
it can be used to automatically enter the manual range mode. In such case, auto shutdown function is disabled
and maximum value is displayed, after another pressing on the button, the minimum value will be displayed and
values are displayed in turn (maximum value-minimum value). When the time of pressing button is ^ 2 s or
switching a range, you'll exit data recording mode (only applicable for V ^ , Q, l^ a n d °C/°F)
7
UT 139A/B/C OPERATING MANUAL
UNI-T
REL button:
it can be used to automatically enter the manual range mode. The current displayed value will be taken as
the reference value and then the difference between the measured value and reference value will be displayed,
after another press, you'll exit the relative measurement mode. (Only applicable for V ^ , Q,
°C/T andHfr)
The backlight will be illuminated when the time of pressing button is ^2 s, after about 15s, the backlight will
be automatically turned off; the backlight will be turned off if pressing the key ^ 2 s when the backlight is
illuminated, (Only applicable for UT139Afull range: REL/LIGHT button)
NCV/mV'V button (Only applicable for UT139A):
It can be used to switch NCV/mV'V. For detailed information, see the operation instruction for non-contact
AC voltage sensing.
Hz/% button (only applicable for UT139B/C):
It can be used to select the mode Hz/%, only applicable for the selection of frequency, AC voltage/ current
measurement modes.
SELECT button:
it can be used to select range (only applicable for multi-range). Under AC mode, press the button ^2s, display
“UFC”, enter V.F.C measurement mode and measure the variable frequency voltage. After another ^ 2 s
pressing on the button, display “End” and exit the V.F.C measurement mode.
HOLD button:
(Applicable for full range)
It can be used to lock and hold the displayed value, in such case, LCD displays the prompt “ E l ”, after another
press, it is unlocked and enter the normal measurement mode.
The backlight will be illuminated when the time of pressing button is ^2s, after about 15s, the backlight will
be automatically turned off; and the backlight will be turned off if pressing the key ^ 2 s when the backlight is
illuminated, (Only applicable for UT139Afull range: HOLD /LIGHT button)
Summary of Contents for TU13BA
Page 1: ...UT139A B C ...
