Instructions
Table Of Contents
- 1 Safety Features and Precautions
- 2 Operating Overview – Connections, Keys, Rotary Switch, Symbols
- 3 Initial Start-Up
- 4 Control Functions
- 5 Measurements
- 5.1 Voltage Measurement
- 5.1.1 Direct and Pulsating Voltage Measurement, V DC and V (DC+AC)
- 5.1.2 Alternating Voltage Measurement with 1 MW Load Resistance and Frequency Measurement with Selectable Low-Pass Filter (METRA HIT Extra, METRA HIT Etech and METRA HIT Especial only)
- 5.1.3 Alternating Voltage and Frequency Measurement V AC and Hz with Selectable Low-Pass Filter (METRA HIT Extra, METRA HIT Etech and METRA HIT Especial only)
- 5.1.4 Frequency and Duty Cycle Measurements (METRA HIT Extra only)
- 5.2 Resistance Measurement, W
- 5.3 Continuity Test
- 5.4 Diode Testing with a Constant Current of 1 mA
- 5.5 Temperature Measurement
- 5.6 Capacitance Measurement (METRA HIT Extra and METRA HIT Etech only)
- 5.7 Current Measurement
- 5.7.1 Direct and Pulsating Current Measurement, Direct Connection, A DC and A (DC+AC) (METRA HIT Extra, METRA HIT Etech and METRA HIT Especial only)
- 5.7.2 Alternating Current and Frequency Measurement, Direct Connection, A AC and Hz (METRA HIT Extra, METRA HIT Etech and METRA HIT Especial only)
- 5.7.3 Direct and Pulsating Current Measurement with Current Clamp Sensors, A DC and A (DC+AC)
- 5.7.4 Alternating Current Measurement with Current Clamp Sensors, A AC and Hz
- 5.7.5 Direct, Pulsating and Current Measurement with Current Clamps Transformer A DC, A (DC+AC), A AC and Hz (METRA HIT Extra, METRA HIT Etech and METRA HIT Especial only)
- 5.1 Voltage Measurement
- 6 Device and Measuring Parameters
- 7 Interface Operation
- 8 Technical Data
- 9 Maintenance and Calibration
- 10 Accessories
- 11 Index
26 GMC-I Messtechnik GmbH
V/Hz, , Temperature, and A/Hz Measurements
5 Measurements
5.1 Voltage Measurement
Notes Regarding Voltage Measurement
• The multimeter may only be operated with installed batteries or
rechargeable batteries. Dangerous voltages are otherwise not
indicated, and the instrument may be damaged.
• The multimeter may only be operated by persons who are
capable of recognizing contact hazards and taking the appropri-
ate safety precautions. Contact hazards exist anywhere, where
voltages of greater than 33 V RMS may occur.
The test probes may only be only gripped up to the finger
guard.
Do not touch the metallic test probes under any
circumstances.
• Avoid working alone when taking measurements which involve
contact hazards. Be certain that a second person is present.
• Maximum permissible voltage (METRAHIT E
XTRA,
METRAHIT ETECH, METRAHIT EBASE)
between the connector sockets,
(9 and 10) and ground (8) is 1000 V for measuring category III,
and 600 V for measuring category IV.
• Maximum permissible voltage (METRAHIT E
SPECIAL)
between the connector sockets (9 and 10) and ground (8) is
600 V for measuring category II.
• Be prepared for the occurrence of unexpected voltages at
devices under test (e.g. defective devices). For example,
capacitors may be dangerously charged.
• No measurements may be made with this instrument in
electrical circuits with corona discharge (high-voltage).
• Special care is required when measurements are made in HF
electrical circuits. Dangerous pulsating voltages may be pres-
ent.
• Be aware of the fact that dangerous voltage spikes are not displayed
during measurement with the low-pass filter.
We recommend measuring voltage without the low-pass filter first, in
order to be able to detect any dangerous voltages.
• Be absolutely certain that the measuring ranges are not
overloaded beyond their allowable capacities. Limit values are
included in chapter 8, “Technical Data”, in the table entitled
“Measuring Functions and Measuring Ranges” in the “Over-
load Capacity” column.
Scope of Functions, Voltage Measurement
1)
A 1 kHz low-pass filter can be used in this case, in order to filter out high
frequency pulses of greater than 1 kHz, for example when performing
measurements at pulsed motor drives.
2)
Input resistance of approx. 1 M. Erroneous displays resulting from
capacitive coupling during voltage measurement in power supply
systems are reduced to a minimum in this way.
Function
METRAHIT
E
XTRA
METRAHIT
E
TECH
METRAHIT
E
SPECIAL
METRAHIT
E
BASE
V AC / Hz TRMS, dB
(Ri 9 M)
1)
V AC / LP filter 1 kHz
1)
(Ri = 1 M
2)
) TRMS
—
V AC+DC TRMS
(Ri 9 M)
V DC (Ri 9 M)
MHz at 5 V AC
———
Duty cycle as %
———
Frequency bandwidth
100kHz 20kHz 20kHz 1kHz