Voltcraft ME-42

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Voltcraft ME-42
Voltcraft ME-42 logo.png
Status supported
Source code serial-dmm
Counts 4000
IEC 61010-1 CAT II (750 V AC/1000 V DC)
Connectivity RS-232 (DB9)
Measurements voltage, current, resistance, diode, continuity
Features autorange, hold, bargraph
Website conrad.de

The Voltcraft ME-42 is a 4000 counts, CAT II (750/1000V) handheld digital multimeter with RS232 connectivity. It is an OEM version of the Metex ME-42. The device was sold by Conrad Elektronik as article 120130 starting from 1999 and is not available any more.

Hardware

Multimeter:

  • TODO
  • Fuses: 800mA/250V 5x20mm and 15A/250V 6x30mm (superfast, ceramic fuses)
  • Battery: 9V NEDA 1604 or 6F22

RS232 cable:

Standard RS-232 cable with DB9 (M) plug.

During tests run by Matthias, this device did not work with several USB to serial converters (tested MosChip, Prolific, FTDI chipsets), only on a real "RS-232" port.

One source on the net [1] reported a very low battery life.

Photos

Multimeter:

Protocol

See Multimeter_ICs#Metex_14-byte_ASCII for the DMM IC protocol.

Model family

It seems that this device belongs to a family of several similiar devices and OEM models.

Metex Conrad PeakTech Radio Shack RMS Frequency Transistor Logic Temp Cap. Remarks
Metex ME-11 - ? RadioShack 22-805 ? ? ? ? ? ? Amps manual range; seems to be similiar to ME-42


Metex ME-21 - ? ? - - - ? Manual Range
Metex ME-22 Voltcraft ME-22 ? ? ? ? Manual Range
Metex ME-22 RMS Voltcraft ME-22 RMS ? ? ? Manual Range
Metex ME-31 - PeakTech 3410 ? ? ? ? ?
Metex ME-32 Voltcraft ME-32 ? ? - - - Amps manual range
Metex ME-42 Voltcraft ME-42 ? ? - - - - - - Amps manual range

Resources

Measurement functions and ranges

Measurement function Range Resolution Accuracy sigrok result Remarks
V= 400.0 mV 100 μV ±(0.5% + 3) mq V, unit V, mqflags DC "
4.000 V 1 mV "
40.00 V 10 mV "
400.0 V 100 mV "
1000 V 1 V "
V≈ 400.0 mV 100 μV ±(1.0% + 5) mq V, unit V, mqflags AC 40 Hz - 100 Hz
4.000 V 1 mV " 40 Hz - 400 Hz
40.00 V 10 mV " "
400.0 V 100 mV " "
750 V 1 V " "
A= 4.000 mA 1 µA ±(0.8% + 3) mq Curr., unit A, mqflags DC
400.0 mA 100 µA ±(1.2% + 3) "
20.00 A 10 mA ±(2.0% + 5) "
A≈ 4.000 mA 10 µA ±(1.0% + 5) mq Curr., unit A, mqflags AC
400.0 mA 100 µA ±(1.5% + 5) "
20.00 A 10 mA ±(3.0% + 5) "
Ω 400.0 Ω 100 mΩ mq Res., unit Ω, mqflags - Continuity beep < 50 Ω
4.000 kΩ 1 Ω "
40.00 kΩ 10 Ω "
400.0 kΩ 100 Ω "
4.000 MΩ 1 kΩ "
40.00 MΩ 10 kΩ "
Diode 2.000 V– 1 mV mq V, unit V, mqflags DC,DIODE Max. 1.5 mA
Data Hold -

The column "sigrok result" contains in short form what the driver generates for the resp. data type.

The device seems to be extremely slow when the RS-232 interface is enabled and often takes up to about 10 seconds to detect a changed value or switch to another range. During this time a previous value keeps being sent. When changing to a new range automatically or manually, the device might send the old value scaled to the new range for a short time. This behaviour is caused by the device, not by sigrok! It improves slightly in manual range.