Gossen Metrawatt Metrahit 27I

Gossen Metrawatt 27I

Status	in progress
Source code	gmc_mh_1x_2x
Counts	31000
IEC 61010-1	CAT II 600 V
Connectivity	Infrared (RS232/USB)
Measurements	voltage, resistance, temperature, diode, continuity
Features	autorange, data hold, backlight, insulation measurement, data logging
Website	[1]

Please note: This page is a work in progress and still partly incorrect.

The Gossen Metrawatt Metrahit 27I is a 3100/31000 counts 600 V CAT II handheld digital multimeter with bidirectional IR (RS232/USB) connectivity. It supports milliohm and insulation (megaohm) measurements and has data logging capabilities.

There are two versions of this device, an older one with yellow rotary switch and a newer one with red rotary switch. They also have different power supply connectors.

Hardware

• Power supply:
  • Battery: 3x 1,2 V NiMH rechargeable batteries
  • External power supply NA HIT 27 (Art. Z218J) by Gossen Metrawatt, 5V, 600 mA (newer version)
• Fuse:
  • FF (UR) 1,6 A/1000 V AC/DC (10 kA) 6,3 mm x 32 mm

Communication Protocol

The complete description is available on request from the manufacturer.

Measurement functions and ranges

Measurement function	Range	Resolution	Accuracy	sigrok result	Remarks
V=	3 V	100 μV	±(0.1% + 10)	mq V, unit V, mqflags DC
	30 V	1 mV	±(0.1% + 5)	"
	300 V	10 mV		"
	600 V	100 mV		"
V≈	3 V	100 μV	±(0.2% + 10)	mq V, unit V, mqflags AC
	30 V	1 mV		"
	300 V	10 mV		"
	600 V	100 mV		"
mΩ@1A	3 mΩ	0.001 mΩ	±(1% + 10)	mq Res., unit Ω, mqflags -	4-wire Kelvin measurement
	30 mΩ	0.001 mΩ	±(0.5% + 10)	"	"
	300 mΩ	0.01 mΩ		"	"
mΩ@200 mA	30 mΩ	0.01 mΩ	±(0.25% + 10)	"	"
	300 mΩ	0.01 mΩ		"	"
	3 Ω	0.1 mΩ		"	"
	30 Ω	1 mΩ		"	"
Ω	300.00 Ω	1 mΩ	±(0.1% + 10)	"	ZERO with yellow button
	3.0000 kΩ	10 mΩ	±(0.1% + 5)	"	"
	30.000 kΩ	100 mΩ		"
	300.00 kΩ	1 Ω		"
	3.0000 MΩ	10 Ω		"
	30.000 MΩ	100 Ω	±(1.5% + 10)	"
MΩ (Insulation)	30 MΩ	10 kΩ	±(2% + 10)	"	Insulation measurement, test voltage selectable 50/100/250/500 V
	300 MΩ	100 kΩ		"	"
	3 GΩ	1 MΩ	±(3% + 10)	"	"
Cont.	310 Ω	100 mΩ	±(1% + 5)	mq Res., unit Ω, mqflags -	Signal < about 10 Ω
Diode	3 V	100 µV	±(1% + 5)	mq V, unit V, mqflags DC,DIODE
Hz	300.00 Hz	0.01 Hz	±(0.05% + 5)	mq Freq., unit Hz, mqflags AC
	3.000 kHz	0.1 Hz		"
°C	Pt100/Pt1000 –200.0 - +100.0 °C	0.1 °C	±(1 K + 5)	mq Temp., unit °C, mqflags -
	Pt100/Pt1000 +100.0 - 850.0 °C		±(0.5K + 5)	"
	Ni 100/Ni1000 -60-+180 °C			"	Not tested yet due to lack of corresponding sensor.
°F	"	"	"	mq Temp., unit °F, mqflags -	Details and ranges like °C.
Data Hold				mqflags += HOLD
MIN				mqflags += MIN
MAX				mqflags += MAX

The Accuracy row was simplified, see manual for exact specs.

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

This device has an uncommon input impendance of 2.1 MΩ in AC/DC volatge measurement modes.