ES237 Datasheet, PDF (25/37 Pages) Cyrustek corporation – 6000 Counts DMM

ES237
6000 Counts DMM
3.7. ZERO Function
In manual DC 6.000A, 60.00A, 600.0A and 6000A, auto DC 60.00A/600.0A, and auto DC
600.0A/6000A (please refer to section 1.5) mesurement modes, ES237 provides ZERO function to
remove the residual current value. Push REL key less than one second to enter ZERO mode. In
ZERO mode, the LCD panel displays D_N+K - D_N, where N = 1, 2, 3, … , D_N is the last conversion
value before REL key is pushed, and D_N+K is the current conversion value. If REL key is pushed
again in ZERO mode, the meter will refresh the D_N value and displays the D_N+K - D_N again. The
meter returns to normal operation if REL key is pressed and held for longer than one second.
Pressing HOLD in ZERO mode makes the meter stop updating the LCD panel. In 2-range auto DCA
modes for clampmeter (600.0A/6000A or 60.00A/600.0A), the system will stay in automatic mode,
even if the ZERO function is activated. In other words, It could achieve real automatic operation. In
automatic mode, ZERO function could not be entered from higher range, but it could be still activated
if current range is lower one. This is because most residual current value is so small that the range
could not be higher one in automatic mode. When enter ZERO mode from lower range, the system
will store the nonzero counts (residual current value). If the range goes up to higher one automatically,
the nonzero counts will be divided by ten. So this function will still work well in automatic modes.
 State diagram for ZEROmode :
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Show D_N+K - D_N
Press Zero < 1s
 State diagram for ZERO + HOLD mode :
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Show D_N+K - D_N
Press Hold
‘Zero’ ‘Hold’ Active
Stop LCD upgrading
Press Zero < 1s
V 2.2
25
2015/12/15