Data Sheet
METRAHIT⏐27M, 27I and H+E CAR
Milliohm Resistance Meter and Digital Multimeter, 
Insulation Tester and Data Logger
4 GMC-I Messtechnik GmbH
Influencing Quantities and Influence Error
)
With zero balancing
1
Specified error valid as of display values of 10% of the measuring range
1
With zero balancing
Real-Time Clock
Accuracy ±1 minute per month
Temperature 
Influence 50 ppm/K
Reference Conditions
Ambient
temperature +23 °C±2K
Relative humidity, 40 ... 60%
Measured quantity
frequency 45 ... 65 Hz
Measured quantity
wave shape Sinusoidal, deviation between RMS and 
rectified value < 0.1%
Storage battery voltage
3.6 V ± 0.2 V
Response Time (after manual range selection) 
* Without parallel connected capacitance
Display
LCD panel (65 mm x 30 mm) with display of up to 3 measured 
values, unit of measure, type of current and various special 
functions.
Display / char. height 7-segment characters
Main display: 12 mm
Auxiliary displays: 7 mm
Number of places  4¾ places, 30999 steps
Overflow display “OL” appears
Polarity display “–” sign is displayed if plus pole
is connected to ⊥
LCD Test All display segments available during 
operation of the METRA HIT 27 are 
activated after the instrument is switched 
on.
Background 
illumination METRA HIT 27I only
Power Supply
Storage batteries 3 ea. 1.2 V/2100 mAh NiMH (AA size)
Service life with 2100 mAh NiMH storage battery set 
Additional consumption for:
Interface operation: 0.5 mA
LCD illumination: 25 mA at 3.6  V. If voltage drops below 
2.7 V, the instrument is switched off 
automatically.
Storage battery test
 is displayed automatically if storage battery 
voltage drops to below approx. 3.3 V
Storage battery charging with NA HIT 2x (Z218H) mains power battery 
charger
 (2100 mAh storage battery set: 
recharging time 20 hours) 
or 
with external NiMH quick charger Z206D: 
recharging time approx. 2 hours
Influencing 
Quantity
Sphere of 
Influence
Measured Quantity /
Measuring Range 
1
Influence Error 
± (... % rdg. + d) / 10 K
Temperature
0 … +21 °C
and
+25… +40 °C
V DC 0.1 + 5
V AC 0.5 + 5
mΩ @ 1 A 4L 1 + 5
mΩ @ 200 mA 4L 1 + 5
300 Ω … 300 kΩ 2L 0.2 + 5
3MΩ 2L 0.5 + 5
30 MΩ 2L 1 + 5
Insulation, 30 MΩ
… 3 
GΩ
2 + 5
Hz 0.1 + 5
°C (RTD) 0.5 + 10
Influencing 
Quantity
Frequency
Measured 
Quantity /
Measuring 
Range
Influence Error 
1
± (... % rdg. + d)
Frequency
V
AC
> 20 Hz ... 45 Hz
3V
to
600.0 V
2 + 10
> 65 Hz ... 1 kHz
Influencing 
Quantity
Sphere of 
Influence
Measured Quantity /
Measuring Range 
1
Influence Error 
Relative 
Humidity
75%
3 days
instrument off
all measured quantities 1 x intrinsic error
Influencing 
Quantity
Sphere of Influence Measuring 
Range
Damping
±dB
Common 
Mode
Interference 
Voltage
Interference quantity max. 600 V ~ V DC > 90 dB
Interference quantity max. 600 V ~
50 Hz, 60 Hz sine
30 V ~ > 80 dB
300 V ~ > 70 dB
600 V ~ > 60 dB
Series Mode
Interference 
Voltage
Interference quantity: V~,
 respective nominal value 
of the measuring range, 
max. 600 V ~, 50 Hz, 60 Hz sine
V= > 60dB
Interference quantity: max. 600 V DC V ~ > 60 dB
Measured 
Quantity /
Measuring 
Range
Response Time
for Digital Display
Measured Quantity
Step Function
V DC, V AC 1.5 s from 0 to 80%
of upper range limit value
mΩ @ 1 A 4L 2 s
from ∞ to 50% 
of upper range limit value
mΩ 1.5 s
300 Ω ... 3 MΩ 2s
3GΩ 
*
5s
 Continuity < 50 ms
1.5 s
°C Pt100 max. 3 s
>10 Hz 1.5 s from 0 to 50% 
of upper range limit value
Measuring Function Current [mA]
/ 3.6 V
Operating Hours 
[h]
V, Hz, Ω, , °C70 30
mΩ @ 1A 700 3
mΩ @ 200mA 260 8
mΩ @ 20mA 85 24
M
Ω 
@ ... V / 1 M
Ω
100 21
Standby (MEM + clock)
0.15 approx. 1 year










