Extech Instruments 420, User Manual

Page: 14 / 16

EX420-EU_ENG V3.1 6/09 14
Function Range Resolution Accuracy
Frequency 5.000Hz 0.001Hz

(1.5% r 5 digits)
50.00Hz 0.01Hz
500.0Hz 0.1Hz

(1.2% r 2 digits)
5.000kHz 0.001kHz
50.00kHz 0.01kHz
500.0kHz 0.1kHz
5.000MHz 0.001MHz

(1.5% r 4 digits)
10.00MHz 0.01MHz
Sensitivity: 0.8V rms min. @ 20% to 80% duty cycle and <100kHz; 5Vrms min @ 20% to
80% duty cycle and > 100kHz.
Duty Cycle 0.1 to 99.9% 0.1%

(1.2% r 2 digits)
Pulse width: 100µs - 100ms, Frequency: 5Hz to 150kHz
Temp
(type-K)
-20 to 750

C 1

C

(3.0% r 3 digits)
(probe accuracy not included)
-4 to 1382

F 1

F
NOTE: Accuracy specifications consist of two elements:

(% reading) – This is the accuracy of the measurement circuit.

(+ digits) – This is the accuracy of the analog to digital converter.
Diode Test Test current of 0.3mA maximum, open circuit voltage 1.5V DC
typical
Continuity Check Audible signal will sound if the resistance is less than 150

(approx.), test current <0.7mA
Temperature Sensor Requires type K thermocouple
Input Impedance
>7.5MΩ (VDC & VAC)
AC Response Average responding
ACV Bandwidth 50Hz to 1kHz
Display 4000 count backlit liquid crystal
Overrange indication “OL” is displayed
Auto Power Off 15 minutes (approximately)
Polarity Automatic (no indication for positive); Minus (-) sign for
negative
Measurement Rate 2 times per second, nominal
Low Battery Indication “ ” is displayed if battery voltage drops below operating
voltage
Battery One 9 volt (NEDA 1604) battery
Fuses mA, µA ranges; 0.5A/250V fast blow
A range; 20A/250V ceramic fast blow
Operating Temperature 5ºC to 40ºC (41ºF to 104ºF)
Storage Temperature -20
o
C to 60
o
C (-4
o
F to 140
o
F)
Operating Humidity Max 80% up to 31ºC (87ºF) decreasing linearly to 50% at
40ºC(104ºF)
Storage Humidity <80%
Operating Altitude 2000 meters (7000ft) maximum.
Weight 342g (0.753lb) (includes holster).
Size 187 x 81 x 50mm (7.36” x 3.2” x 2.0”) (includes holster)
Safety For indoor use and in accordance with the requirements for
double insulation to IEC1010-1 (2001): EN61010-1 (2001)
Overvoltage Category III 600V and Category II 1000V,
Pollution Degree 2.