GMC MetraHIT 27I Insulation Tester, Milliohmmeter, Multimeter and Data Logger

GMC MetraHIT 27I Insulation Tester, Milliohmmeter, Multimeter and Data Logger

The MetraHit 27I is a compact milliohm resistance meter plus multimeter, insulation resistance tester and
thermometer for the measurement of low-value contact resistance on aircraft outer skins (lightning protection,
wick test), and for general low-resistance measurements. The METRA HIT 27I is used additionally
for service and repair work performed on airplane and helicopter electrical systems (voltage, insulation,
milliohm and temperature measurement). In addition to its own multimeter functions for electrical
quantities, the instrument also includes a mega-ohm measuring function with insulation test voltages
of 50, 100, 250 and 500 V, as well as temperature measurement with P-t100 and Pt-1000 sensors.

Features:

• All-in-one: milliohm resistance meter, multimeter, insulation tester and data logger
• Compact and rugged for service under harsh conditions and laboratory use
• Kelvin connection (4-wire measurement) Eliminates contact resistances on measuring results
• Measuring current can be selected according to the measuring task
• Adaptation to various resistance measuring requirements and optimized battery service life
• DATA Hold For quick, reliable measurement and storage of individual measured values
• Overload protection Protects the instrument in the event of inadvertent connection to AC power
• NIST calibration certificate option
• Operation with storage batteries3 NiMH storage batteries are included as a standard feature.
• Insulation resistance tester, Testing with 50 to 500 V for components, ideal for aircraft electrical systems
• LCD panel with background illumination High contrast, even under adverse ambient light conditions
• Compact and multifunctional Can be used advantageously in aircraft cockpitsand other constricted spaces
• AC power or storage battery operation
• Insulation resistance measurement 30.00 MOhm to 3.000 GOhm with test voltage of 50, 100, 250 or 500 V
• Milliohmmeter - 3.000 mOhm to 300.00 mOhm with 1 A measuring current
• 30.00 mOhm to 30.00 Ohm with 200 mA measuring current
• Resistance measurement from 300 Ohm to 30 MOhm
• Voltage measurement from 3 to 600 V DC and 3 to 600 V AC with +/- 30,000 digits
• Frequency measurement from 300 Hz to 3 kHz

The METRA HIT 27 milliohm resistance meters are the modern alternative for the well known
TH2 (Thomson) and Wh2 (Wheatstone) measuring bridges. They provide an expanded measuring
range, greater accuracy and easier reading. As universal measuring and test instruments, they acquire
and record values to an integrated memory module including resistance in the milliohm and micro-ohm
ranges, as well as "normal multimeter resistance values" in the ohm to mega-ohm ranges by feeding a
measuring current to the resistor, conductor or contact under test. The respective measuring current is
determined by the rotary selector switch setting and lies within a range of 1 to 0.02 A in the milliohm
ranges. The instrument also measures and records insulation resistance (METRA HIT 27I only) with test
voltage selectable in steps, for example in order to test resistance in on-board electrical systems for aircraft,
ocean going vessels etc., and for testing overvoltage arresters and much more.

Easy Operation - Operation is very easy. Simply connect the low-resistance device under test to the
instrument with the included measurement cables, Kelvin clips or 4-pole probes (KC27), and select the
ideal measuring range.

Integrated Measured Value Memory and Interface - Each METRAHit27 is equipped with a measured
value memory module and can thus be utilized as a data logger or a recording instrument for all measuring
functions. Measurement results can be transmitted to a PC either off-line via the optical interface which is
furnished as standard equipment, or online with an optional bidirectional adapter. In this way, for example,
characteristic voltage and temperature curves can be displayed and analyzed in line recorder format relative
to real-time, or individual measured values, e.g. voltages for each of the cells in a storage battery, can be
saved with the DATA Hold function and analyzed at a PC in tabular form.METRAwin®10/METRAHit®
(software option):Recorded characteristic temperature curve and triggering characteristics (2-channel
recording with 2 METRA HIT instruments) plus evaluation at a PCMETRAwin®10/METRAHit®

Software Option - Measurement data recorded to the measured value memory module can be evaluated
at a PC if required with the help of the IR interface supplied as standard equipment and a bidirectional IR
adapter (BD adapter) with conversion to the RS 232 protocol. METRAwin®10/METRAHit® software is
recommended to this end, and is suitable for display, analysis and documentation of measurement results
using Windows® 98,NT, 2000 or XP. The software is available as an accessory. User-friendly complete
packages (e.g. the BD Pack or thecomplete METRA HIT 27AS case) are easy to connect and install and
include everything required for high performance measurement data processing.

Offset Balancing - Automatic offset balancing is provided for the lower measuring ranges. Manual
offset balancing, as required with the METRA HIT17 predecessor model, is thus no longer necessary.

Protection Against Operator Error - The METRA HIT 27 is safeguarded against erroneous
short-term connection to devices under test with fault voltages of up to 600 V by means of protective devices.

Test Functions and Automatic Functions - All METRA HIT 27 instruments are equipped with diode and
continuity test functions, as well as automatic and manual measuring range selection and battery shutdown.

Applications:

The METRA HIT 27 is a compact, rugged and reliable instrument, which is equally suitable for precision
measuring and recording tasks in the factory, for on-site service and in the laboratory:

• Adjustment of shunts in instrumentation
• Testing of electrical connections at conductor bars  in potential bonding systems
• Testing of cable resistance, wiring, shunt resistors in PCBs and thick-film circuits
• Measurement of contact resistance in relays, contactors and power interrupters
• Testing of resistance in fuses, as well as conductor resistance in heavy current circuits
• Testing of winding resistance in transformers, coils, small motors etc.
• Testing of discharge resistance on aircraft, and at aircraft outer skin components
• Contact resistance testing in uninterruptible power supplies
• Measurement of cell voltages, for example in on-board batteries and emergency power supplies
• Contact resistance testing at welding seams

Avionics Test Set - MetraHIT 27AS

The MetraHit 27AS is a kit assembled specifically for the Avionics test industry. All the tools required to test
aircraft are included in onecompact carry case kit (shown below):

GMC MetraHIT 27I Data Sheet