Operating Instructions METRAHIT⏐27 METRA HIT 27M: Digital Multimeter and Milliohmmeter METRA HIT 27I: Digital Multimeter, Milliohmmeter and Megohmmeter 3-349-207-02 8/12.
3 4 5 6 10 1 9 7 8 1 2 3 4 5 6 2 Symbols used in the Digital Display 1 Main display with decimal point and polarity display 2 Auxiliary display with decimal point and polarity display 3 7 max.
Table of Contents Page Page 1 Safety Features and Precautions ...............................4 2 Initial Start-Up ............................................................5 3 Selecting Measuring Functions and Measuring Ranges .......................................................................6 3.1 3.2 3.3 Automatic Measuring Range Selection ..................................... 6 Manual Measuring Range Selection ......................................... 6 Quick Measurements .................
1 Safety Features and Precautions You have selected an instrument which provides you with high levels of safety. This instrument fulfills the requirements of the applicable European and national EC guidelines. We confirm this with the CE marking. The relevant declaration of conformity can be obtained from GMC-I Messtechnik GmbH. The METRA HIT27 is manufactured and tested in accordance with safety regulations IEC 61010–1:2001 / DIN EN 61010–1:2001 / VDE 0411–1:2002.
Meanings of symbols on the instrument: ! + Warning concerning a source of danger (attention: observe documentation!) Initial Start-Up Storage Batteries or Batteries Refer to chapter 14.1 regarding correct storage battery or battery installation.
Setting Time and Date See chapter 12 on page 17. Switching the Instrument Off Manually Ð Press and hold the ON|OFF key until OFF appears at the display. Shutdown is acknowledged with two, brief acoustic signals. Switching the Instrument Off Automatically – SLEEP MODE The instrument is switched off automatically if none of the keys or the rotary switch are activated for approximately 10 minutes. Shutdown is acknowledged with a brief acoustic signal.
3.3 Quick Measurements If you wish to perform quicker measurements than those possible with the automatic measuring range selection function, make sure to establish the appropriate measuring range: • by manual measuring range selection, i. e. by selecting the measuring range with the best resolution, see chapter 3.2. or • via DATA function, see chapter 5.
5 Measured Value Storage The METRA HIT27 provides two entirely different options for storing data: • Measured Value Memory – DATA Key Function: Each time a measuring point is contacted, a measured value is stored in accordance with a defined condition (see chapter 5.1). • Memory Mode Operation – STORE Menu Function: After activating the STORE menu function, all measured values are saved in accordance with the selected sampling rate.
6 Saving Minimum and Maximum Values “MIN/MAX” with Time Stamp 30.000 Minimum and maximum values can be displayed at the auxiliary displays for long-term observation of measured quantities. Ð Press the DATA|CLEAR key twice: Current MIN and MAX values appear at the auxiliary displays. Automatic range selection is disabled as long as the MIN/MAX function is active. Ð Press the DATA|CLEAR key once again for a display of the minimum value and the time of its occurrence.
226.000 V~ Hz V FUNC 050.00 FUNC Hz 7.1 Voltage Measurement [V] Ð Select voltage type V or V~/Hz with the rotary selector switch as appropriate for the measured quantity. Ð Connect the measurement cables as shown. The “⊥” connector jack should be grounded. Ð The V~/Hz selector switch position: Each time the FUNC key is pressed, voltage and frequency measurement are alternately selected, and switching is acknowledged with an acoustic signal. The respective measured quantity is displayed at the LCD.
7.2 Frequency Measurement [Hz] Ð Select the V~/Hz measuring function with the rotary selector switch. Ð Apply the measured quantity as described under voltage measurement. Ð Briefly press the FUNC key in order to measure frequency. The frequency values appears at the main display. The frequency measuring range can be selected subsequently by pressing MAN|AUTO. The previously selected voltage measuring range remains active.
8.2 Continuity Test during Resistance Measurement If the “acoustic signal ” function is activated and the 0 ... 310 Ω measuring range is selected, a continuous acoustic signal is generated by the instrument within a range of 0 to approx. 10 Ω. Overflow “0l” is displayed where Rd > 310 Ω. Activating and Deactivating Continuity Testing (acoustic signal) Ð Set the rotary selector switch to „Ω/ / “.
9 Milliohm Measurement (4-Pole-Measurement) 9.1 Compensation of Cable Resistance Electrical resistance is a dipole quantity which can generally only be measured using two poles. This is accomplished by directing a measuring current of predetermined magnitude through the device under test, and measuring the resultant voltage drop. The respective resistance value is derived from the quotient of these two values.
9.3 Milliohm Measurement with 200 mA or 20 mA DC [mΩ] Ð Make sure that the device under test is voltage-free (see chapter 7.1). Interference voltages distort measurement results! Ð Set the rotary selector switch to “mΩ”. Ð Connect the device under test as shown. KC4 Kelvin clips and KC27 Kelvin probes (available as accessories) allow for easy, correct connection. Resistance at the current jacks should amount to < 1 Ω.
11 Measuring Range: mΩ S– Insulation Resistance Measurement [MΩ@...V] (METRA HIT 27I only) S+ VΩ°C see chapter 14 MΩ@ 50 ... 500V - ---- -000 V 250V Selected Test Voltage RTD Adjusting Cable Resistance Ð After selecting a resistance thermometer, the measurement display is accessed by pressing the key. Ð The menu for cable resistance adjustment is opened by simultaneously pressing the and keys. Rlead and temp are displayed. Ð The decade (i.e.
Note! Testing the Measurement Cables Initial testing should be performed by short-circuiting the measurement cables using their test probes. The instrument must display nearly 0 Ω. A broken measurement cable can be detected in this way. mΩ S– S+ MΩ Measuring Range: Ω: 10 kΩ … 3 GΩ UMeasured (50 to 500V) RISO ! ! 16 Attention! Do not touch the conductive ends of the test probes when the instrument has been activated for the measurement of insulation resistance.
12 Using the Menus – from the Initial InFO Menu to Operating and Measuring Parameters Menu-driven operation via the initial „1NF0“ menu allows the user to query online help, activate the memory and query memory occupancy, activate the interface and configure device parameters. Ð The initial „1NF0“ menu is accessed by simultaneously pressing and holding the FUNC and ON|OFF keys with the instrument switched on, until „1NF0“ appears at the display.
12.2.2 Memory Mode Operation – STORE Menu Function Ð First set the sampling rate for memory mode operation, and then start memory mode operation. The sampling rate can also be changed during memory mode operation. Ð First select the desired measuring function and an appropriate measuring range. Ð Check the storage battery charge level before starting long-term measurement recordings, see chapter 14.1 on page 25. Connect the charger if necessary.
12.6 Transmission Mode Operation with RS 232 Interface The METRA HIT27 is equipped with an bidirectional infrared interface for the transmission of measurement data to a PC. Data are transferred optically through the instrument housing by means of infrared light to an interface adapter (accessory USB-HIT), which is attached to the instrument. The adapter’s USB-HIT-interface allows for the establishment of a connection to the PC via an interface cable.
Main Menus and Submenus FUNC + ON Query Information 2x 1nf0 ↵ 3.9 V batt Storage Battery Charge Level t im e 8 01 mem0 12:58 :08 oCCUp Memory Occupancy (see chapter 12.3) Current Time date 1508.02 tCal 1508.02 Current Date tadJ 1508.
SEt Submenu for rAtE, Addr, dAtE and tIME Parameters Continued from previous page Set Sampling Rate (see also chapter 12.1) set set rate 00:10:00 rate Change Value Acknowledge Sampling Rate Possible Settings (hh:mm:ss, h = hours, m = minutes, s = seconds) 00:00:01, 00:00:02, 00:00:05, 00:00:10, 00:00:20, 00:01:00 00:02:00, 00:05:00, 00:10:00, 00:20:00, 01:00:00; 0.
13 Characteristic Values Measuring Measuring Range Function V mΩ@1A (4 L) mΩ (4 L) Ω (2 L) MΩ@ ...V Resolution at Upper Range Limit 4¾ 30000 / 3¾ 3000 100 μV 1 mV 10 mV 100 mV 3 30 300 600 V V V V 3 30 300 30 300 3 30 300 3 30 300 3 30 300 mΩ mΩ mΩ mΩ mΩ Ω Ω Ω kΩ kΩ kΩ MΩ MΩ Ω 0.001 0.001 0.01 0.01 0.01 0.1 1 10 100 1 10 100 1 0.1 mΩ mΩ mΩ mΩ mΩ mΩ mΩ mΩ mΩ Ω Ω Ω kΩ Ω 3 V 0.1 mV 30 MΩ 300 MΩ 3000MΩ 10) 0.01 MΩ 0.1 MΩ 1 MΩ 1) Input Impedance 6) DC 2.1 MΩ 2.1 MΩ 2.1 MΩ 2.
Influencing Quantities and Influence Error Influencing Quantity Temperature Sphere of Influence Measured Quantity / Measuring Range 1) Influence Error ± (... % rdg. + d)/10 K V DC 0.1 + 5 V AC 0.5 + 5 mΩ@ 1 A 4L 1+5 0 … +21 °C mΩ@ 200 mA 4L 1+5 and 300 Ω … 300 kΩ 2L 0.2 + 5 3 MΩ 2L 0.5 + 5 +25… +40 °C 1) Frequency VAC 1) 1+5 2+5 Hz 0.1 + 5 °C (RTD) 0.5 + 10 Measured Quantity / Measuring Range Frequency > 20 Hz ... 45 Hz > 65 Hz ...
Power Supply Storage batteries 3 ea. 1.2 V NiMH storage batteries (AA size) (≥ 2100 mAh) Service life with set of 2100 mAh NiMH storage batteries Measuring Function V, Hz, Ω, Current Service Life [h] [mA] / 3.6 V , °C 70 30 mΩ@1A 700 3 mΩ@200mA 260 8 mΩ@20mA 85 24 MΩ@ ... V / 1 MΩ 100 21 Standby (MEM + clock) 0.15 approx. 1 year 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.
14 Maintenance ! Attention! Disconnect the instrument from the measuring circuit before opening to replace storage batteries, batteries or fuses! 14.1 Storage Batteries and Batteries Warning! The mains power battery charger may not be connected if normal batteries have been installed instead of storage batteries: Danger of explosion! Removing the Storage Batteries During Periods of Non-Use The integrated quartz clock draws power from the storage batteries, even when the instrument is switched off.
14.2 Fuses The fuse is located at the measuring input. When the fuse is defective, the measurements in the mΩ/Ω/ / ranges are faulty. The error in the V range amounts to only 10%. If a fuse should blow, eliminate the cause of overload before placing the instrument back into service! Inspecting the Integrated Fuse Ð Set the rotary switch to the Ω measuring function. Ð Short circuit the ⊥ and Ω jacks. Display < 0.2 Ω: fuse OK Display approx.
16 Accessories The BD232 interface adapter (without memory) allows for remote control of the instrument, as well as transmission of measurement data from up to six multimeters to a PC (in the online operating mode with METRAwin10). Interface adapter USB-HIT is functionally identical to the BD232 interface adapter, although bidirectional transmission takes place between the IR and the USB interface in this case. The driver to be installed assigns a virtual COM interface to the instrument.
18 Guarantee 20 The guarantee period for all METRA HIT measuring and calibration instruments is 3 years after date of shipment. Calibration is guaranteed for a period of 12 months. The guarantee covers materials and workmanship. Damages resulting from use for any other than the intended purpose or operating errors, as well as any and all consequential damages, are excluded.
