Voltcraft ME-42
| Status | in progress |
|---|---|
| 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 also did not work with several USB to serial converters (tested MosChip, Prolific, FTDI chipsets), only on a real "RS-232" port.
Photos
Multimeter:
Protocol
See Multimeter_ICs#Metex_14-byte_ASCII for the DMM IC protocol.
It seems that the device does not work with some RS232-USB converters.
Model family
It seems that several versions and OEM models exist.
| Metex | Conrad | PeakTech | Radio Shack | RMS | Frequency | Transistor | Remarks |
|---|---|---|---|---|---|---|---|
| Metex ME-11 | - | ? | RadioShack 22-805 | ? | ? | ? |
|
| Metex ME-21 | - | ? | ? | ? | ? | ? | |
| Metex ME-22 | Voltcraft ME-22 | ? | ? | ● | ? | ? | |
| Metex ME-31 | - | PeakTech 3410 | ? | ? | ? | ? | |
| Metex ME-32 | Voltcraft ME-32 | ? | ? | ? | ? | ? | |
| Metex ME-42 | Voltcraft ME-42 | ? | ? | - | - | - |
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 | |
| 300.0 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 is extremely slow 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 operating the Range Hold button, the device might send the old value scaled to the new range for a few times. This behaviour is caused by the device, not by sigrok!