Gossen Metrawatt Metrahit 28S

Gossen Metrawatt Metrahit 28S

Status	in progress
Counts	310000
IEC 61010-1	CAT III 1000 V, CAT IV 600 V
Connectivity	Infrared (RS232)
Measurements	voltage, current, resistance, capacitance, temperature, diode, continuity, insulation
Features	autorange, data hold, bargraph, backlight
Website	[1]

The Gossen Metrawatt Metrahit 28S is a 310000 counts handheld digital multimeter with IR (RS232) connectivity.

Hardware

• Fuse:
  • Current 300 mA: FF (UR) 1,6 A/1000 V AC/DC (10 kA) 6,3 mm x 32 mm
  • Current 3A/10A: FF (UR) 10 A/1000 V AC/DC (30 kA) 10 mm x 38 mm

• TODO.

Measurement functions and ranges

Note: Work in progress, currently simply wrong!

Measurement function	Range	Resolution	Accuracy	sigrok result	Remarks
V=	300 mV	1 μV	±(0,02% + 0,010% + 5)	mq V, unit V, mqflags DC
	3 V	10 μV	±(0,02% + 0,005% + 5)	"
	30 V	100 μV		"
	300 V	1 mV		"
	1000 V	10 mV		"
V≈	300 mV	10 µV	±(0,5% + 30) (> 500 Digit))	mq V, unit V, mqflags AC,RMS
	3 V	100 μV	±(0,2% + 30)	"
	30 V	100 μV		"
	300 V	1 mV		"
	1000 V	10 mV		"
V≃	300 mV	10 μV	±(0,5% + 30) (> 500 Digit))	mq V, unit V, mqflags AC,DC,RMS
	3 V	100 μV	±(0,2% + 30)	"
	30 V	100 μV		"
	300 V	1 mV		"
	1000 V	10 mV		"
V db≈	-48 - 63 dB	0,01 dB		mq V, unit V, mqflags AC,RMS	Actually the 5 AC ranges, see there for accuracy.
V db≈ rel	-48 - 63 dB	0,01 dB		mq V, unit V, mqflags AC,RMS	Actually the 5 AC ranges, see there for accuracy. To activate, press yellow button in dB mode, then do second measurement. Cannot be distinguished from non-rel measurement remotely.
A=	300.00 µA	1 nA		mq Curr., unit A, mqflags DC
	3.0000 mA	10 nA		"
	30.000 mA	100 nA		"
	300.00 mA	1 µA		"
	3.0000 A	100 µA		"
	10.000 A	1 mA		"
A≃	300.00 µA	10 nA		mq Curr., unit A, mqflags AC,DC,RMS
	3.0000 mA	100 nA		"
	30.000 mA	1 µA		"
	300.00 mA	10 µA		"
	3.0000 A	100 µA		"
	10.000 A	1 mA		"
Ω	300.00 Ω	1 mΩ		mq Res., unit Ω, mqflags -
	3.0000 kΩ	10 mΩ		"
	30.000 kΩ	100 mΩ		"
	300.00 kΩ	1 Ω		"
	3.0000 MΩ	10 Ω		"
	30.000 MΩ	100 Ω		"
Ohm/Cont.	300 Ω	100 mΩ		mq Res., unit Ω, mqflags -
Diode/Cont.	300 mV	100 µV		mq V, unit V, mqflags DC,DIODE
Diode	3 V	100 µV		mq V, unit V, mqflags DC,DIODE
Cap. F	3.000 nF	1 pF		mq Cap., unit F, mqflags -
	30.00 nF	10 pF		"
	300.0 nF	100 pF		"
	3.000 µF	1 nF		"
	30.00 µF	10 nF		"
	300.0 µF	100 nF	±(5.0% + 6)	"
	3.000 mF	1 µF		"
	30.00 mF	1 µF		"
Hz≃	300.00 Hz	0.001 Hz	±(0.05% + 1)	mq Freq., unit Hz, mqflags AC,DC
	3.0000 kHz	0.01 Hz		"
	300.000 kHz	1 Hz		"
°C	Pt100/Pt1000 –200.0 - +100.0 °C	0.1 °C	±(0,5 K + 3)	mq Temp., unit °C, mqflags -
	Pt100/Pt1000 +100.0 - 850.0 °C		±(0,2% + 3)	mq Temp., unit °C, mqflags -
	K NiCr-Ni -270-+1372,0 °C		±(0,7% + 3)	"
	J Fe-CuNi -210 - +1200.0 °C		±(0,8% + 3)	"
°F				mq Temp., unit °C, mqflags -	Not tested yet.
Event count				mq V, unit V, mqflags AC,RMS,REL	Counts events >= 2500 digits that last >=2s with a break >=2s. To activate, switch to voltage ACDC, press yellow button twice. Press up to 4 times to cycle parameters, press long to stop. See manual. Not useful remotely because the current measurement value is sent, not the counter.
Stop Watch		100 ns		(Time data)	Max. 100 Min. To activate, select a 3V-1000V≃ range manually, press yellow button, press AUTO for start/stop, DATA for reset. Delivers only invalid data ("Overflow") via IR on  Matthias' test device.
Data Hold				mqflags += HOLD	Disabled while IR interface is active on  Matthias' test device.
MIN				mqflags += MIN	Influences only display, via IR flag is set, but actual current value is delivered.
MAX				mqflags += MAX	Influences only display, via IR flag is set, but actual current value is delivered.

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