Gossen Metrawatt M246C, METRAHIT COIL User guide

Operating Instructions

METRAHITISO and METRAHITCOIL

TRMS Multimeter with Insulation and Interturn Short-circuit Measurement (METRAHITCOIL only)

3-349-416-03

15/5.17

Standard Equipment Contact Persons

1kHz

Standard Equipment METRAHIT ISO

1 Multimeter for isolation measurement 1 Protective rubber cover 1 KS17-2 cable set 1 DAkkS calibration certificate with calibration report 2 Batteries, 1.5 V, type AA, installed 1 Condensed operating instructions *

Standard Equipment METRAHIT COIL

1 Insulation multimeter 1 Protective rubber cover 1 KS17-2 cable set 1 DAkkS calibration certificate 2 Batteries 1.5 V, type AA, installed 1 COIL TEST ADAPTER for interturn short-circuit measurement 1 Condensed operating instructions *

* Detailed operating instructions are available for download on the Internet

at www.gossenmetrawatt.com

Function METRAHITISO METRAHIT COIL V AC+DC TRMS (Ri = 1 M) V AC / Hz TRMS (Ri  9 M)



V AC+DC TRMS (Ri

9 M)

V DC (Ri  9 M) Hz (V AC) Bandwidth V AC A AC / Hz TRMS A AC+DC TRMS A DC Fuse Transformation factor Hz (A AC) Insulation Resistance M

ISO

Interturn short-circuit measurement M



COIL

Duty cycle measurement % Resistance  Continuity Diode ... 5,1 V Tem p er at ur e

TC (K) Temperature RTD Capacitance MIN/MAX / data hold 4 MBit memory

IR Interface Power pack adapter socket Protection Measuring category

For 15,000 measured values, sampling rate adjustable from 0.1 second to 9 hours

1000 V CAT II, 600 V CAT III



Filter

 

... 300 kHz ... 300 kHz

15 Hz ... 10 kHz 15 Hz ... 10 kHz

300 A

3/30/300 mA

3 A / 10 A

10 A/1000 V 10 A/1000 V

mV/A, mA/A mV/A, mA/A

... 30 kHz ... 30 kHz

adjustable test voltage adjustable test voltage

— 

         

IP54 

Filter

300 A

3/30/300 mA

3 A / 10 A

IP54

2 GMC-I Messtechnik GmbH

Contact Persons

Accessories (sensors, plug inserts, adapters, consumable materials)

The accessories available for your instrument are checked for compliance with currently valid safety regulations at regular intervals, and are amended as required for new applications. Currently up-to-date accessories which are suitable for your measuring instrument are listed at the following web address along with photo, order number, description and, depending upon the scope of the respective accessory, data sheet and operating instructions: www.gossenmetrawatt.com

See also chapter 9.6 on page 71.

Repair and Replacement Parts Service Calibration Center* and Rental Instrument Service

If required please contact:

GMC-I Service GmbH

Service Center

Thomas-Mann-Str. 16-20 90471 Nuremberg, Germany Phone: +49 911 817718-0 Fax: +49 911 817718-253 E-mail service@gossenmetrawatt.com www.gmci-service.com

This address is only valid in Germany. Please contact our representatives or subsidiaries for service in other countries.

* DAkkS Calibration Laboratory for Measured Electrical Quantities

D-K-15080-01-01 accredited per DIN EN ISO/IEC 17025

Accredited quantities: direct voltage, direct current value, direct current resistance, alternating voltage, alternating current value, AC active power, AC apparent power, DC power, capacitance, frequency, temperature

4 GMC-I Messtechnik GmbH

Competent Partner

GMC-I Messtechnik GmbH is certified in accordance with DIN EN ISO 9001.

Our DAkkS calibration laboratory is accredited by the Deutsche Akkreditierungsstelle GmbH (National accreditation body for the Federal Republic of Germany) in accordance with DIN EN ISO/IEC 17025 under registration number D-K-15080-01-01.

We offer a complete range of expertise in the field of metrology: from test reports and factory calibration certificates, right on up to DAkkS calibration certificates.

Our spectrum of offerings is rounded out with free test equipment management.

As a full service calibration lab, we can calibrate instruments from other manufacturers as well.

Contact Persons

GMC-I Messtechnik GmbH 5

Table of Contents

Contents Page Contents Page

1 Safety Features and Precautions ....................................... 8

1.1 Use for Intended Purpose ................................................................10

1.2 Meanings of Danger Symbols ..........................................................10

1.3 Meanings of Acoustic Warning Signals ............................................10

Operating Overview – Connections, Keys, Rotary Switch, Symbols 12

3 Initial Start-Up .................................................................. 16

3.1 Batteries ........................................................................................16

3.2 Activation .......................................................................................16

3.3 Setting the Operating Parameters ....................................................16

3.4 Switching the Instrument Off ...........................................................17

4 Control Functions ............................................................. 18

4.1 Selecting Measuring Functions and Measuring Ranges .....................18

4.1.1 Automatic Range Selection .............................................................18

4.1.2 Manual Measuring Range Selection .................................................18

4.1.3 Quick Measurements ......................................................................19

4.2 Zero Offset / Relative Measurements ...............................................19

4.3 Display (LCD) .................................................................................20

4.3.1 Digital Display ................................................................................20

4.3.2 Analog Display ...............................................................................20

4.4 Measured Value Storage: DATA (auto-hold / compare) ......................21

4.4.1 Function DATA during insulation measurement * ..............................22

4.4.2 Saving Minimum and Maximum Values – MIN/MAX Function ............23

4.5 Measurement Data Recording .........................................................24

5 Measurements ................................................................. 26

5.1 Voltage Measurement ....................................................................26

5.1.1 Direct and Pulsating Voltage Measurement, V DC and V (DC+AC) .....27

5.1.2 Alternating Voltage and Frequency Measurement V AC and Hz

with Selectable Low-Pass Filter .......................................................28

5.2 Resistance Measurement, 

5.3 Temperature Measurement: Temp RTD and Temp TC ......................33

5.3.1 Measurement with Resistance Thermometers ..................................33

5.3.2 Measurement with Thermocouples, Temp TC ..................................35

5.4 Continuity Test ..............................................................................36

5.5 Diode Testing with Constant Current of 1 mA ..................................37

5.6 Capacitance Measurement ............................................................38

5.7 Insulation Resistance Measurement – M

5.7.1 Preparing for Measurement ............................................................39

5.7.2 Performing the Insulation Measurement ..........................................40

5.7.3 Ending the Measurement and Discharging ......................................41

5.8 Interturn Short-circuit Measurement – Function

5.8.1 Preparing the Measurement ...........................................................42

5.8.2 Performing Interturn Short-circuit Measurement ...............................43

5.8.3 Ending the Measurement and Discharging .......................................45

5.9 Current Measurement ....................................................................46

5.9.1 Direct and Pulsating Current Measurement, Direct Connection,

A DC and A (DC+AC) ......................................................................47

5.9.2 Alternating Current and Frequency Measurement,

Direct Connection, A AC and Hz ......................................................48

5.9.3 Direct and Pulsating Current Measurement

with Clip-On Current Sensor A DC and A (DC+AC) ...........................49

@UISO ....................................... 39

COIL/M



@UISO ...........42

6 GMC-I Messtechnik GmbH

Table of Contents

Contents Page Contents Page

5.9.4 Alternating Current Measurement with Clip-On Current Sensor,

A AC and Hz .................................................................................. 50

5.9.5 Alternating Current Measurement with A AC and Hz Clip-On

Current Transformer ......................................................................51

6 Device and Measuring Parameters ................................... 52

6.1 Paths to the Various Parameters .................................................... 53

6.2 List of All Parameters .................................................................... 53

6.3 Querying Parameters – InFo Menu (as moving letters) ...................... 54

6.4 Entering Parameters – SETUP Menu ............................................... 55

6.5 Default Settings ............................................................................. 57

7 Interface Operation ........................................................... 58

7.1 Activating the Interface ...................................................................58

7.2 Configuring Interface Parameters .................................................... 59

8 Technical Data ................................................................ 60

9 Maintenance and Recalibration ........................................ 68

9.1 Displays – Error Messages ............................................................ 68

9.2 Batteries .......................................................................................68

9.3 Fuses ............................................................................................69

9.4 Housing Maintenance ....................................................................70

9.5 Return and Environmentally Sound Disposal .................................... 70

9.6 Recalibration .................................................................................71

9.7 Manufacturer’s Guarantee .............................................................. 71

10 Accessories .......................................................................72

10.1 General ......................................................................................... 72

10.2 Technical Data for Measurement Cables

(scope of delivery: KS17-2 safety cable set) .................................... 72

10.3 Power Pack NA X-TRA (not included) .............................................. 72

10.4 Interface Accessories (not included) ................................................ 73

11 Index .................................................................................74

GMC-I Messtechnik GmbH 7

Safety Warnings

1 Safety Features and Precautions

You have selected an instrument which provides you with a high level of safety.

This instrument fulfills the requirements of the applicable European guidelines and national regulations. This is confirmed by means of the CE mark. A corresponding declaration of conformity can be requested from GMC-I Messtechnik GmbH.

The TRMS digital multimeter has been manufactured and tested in accordance with the following safety regulations: IEC 61010–1:2010/DIN EN 61 010–1:2011/VDE 0411–1:2011. When used for its intended purpose (see page 10), safety of the operator, as well as that of the instrument, is assured. Their safety is however not guaranteed, if the instrument is used improperly or handled carelessly.

In order to maintain flawless technical safety conditions, and to assure safe use, it is imperative that you read the operating instructions thoroughly and carefully before placing your instrument into service, and that you follow all instructions contained therein.

The multimeter is equipped with an automatic socket blocking mechanism for your safety, and in order to safeguard your instrument. This mechanism is linked to the rotary switch and only allows access to those jacks which are actually required for the selected function. It also prevents the user from turning the rotary switch to impermissible functions after the measurement cables have already been plugged in.

Measuring Categories and their Significance per IEC 61010-1

CAT Definition

Measurements in electrical circuits which are not directly connected to the

mains: e.g. electrical systems in motor vehicles and aircraft, batteries etc.

Measurements in electrical circuits which are electrically connected to the

low-voltage mains: via plug, e.g. in household, office and laboratory applications

Measurements in building installations: stationary consumers, distributor

III

terminals, devices connected permanently to the distributor

The measuring category and the maximum rated voltage which are printed on the device apply to your measuring instrument, e.g. 600 V CAT II I or 1000 V CAT II.

For the application of measuring cables see page 72.

Observe the following safety precautions:

• The multimeter may not be used in potentially explosive atmospheres.

• The multimeter may only be operated by persons who are capable of recognizing contact hazards and taking the appropriate safety precautions. Contact hazards according to the standards exist anywhere, where voltages of greater than 33 V RMS or 70 V DC may occur. Avoid working alone when taking measurements which involve contact hazards. Be certain that a second person is present.

• Maximum allowable voltage between the voltage measuring sockets or all connector sockets and ground is 1000 V for measuring category II, and 600 V for measuring category I I I.

• Be prepared for the occurrence of unexpected voltages at devices under test (e.g. defective devices). For example, capacitors may be dangerously charged.

8 GMC-I Messtechnik GmbH

Safety Warnings

• Make certain that the measurement cables are in flawless condition, e.g. no damage to insulation, no interruptions in cables or plugs etc.

• 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 present.

• Measurements under moist ambient conditions are not permitted.

• 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 “Overload Capacity” column.

• The multimeter may only be operated with installed batteries or rechargeable batteries. Dangerous currents and voltages are otherwise not indicated, and the instrument may be damaged.

• The instrument may not be operated if the fuse cover or the battery compartment lid has been removed, or if its housing is open.

• The input for the current measuring range is equipped with a fuse link. Maximum permissible voltage for the measuring circuit (= rated voltage of the fuse) is 1000 V AC/DC. Use specified fuses only (see page 65)! The fuse must have a

breaking capacity of at least 30 kA.

Opening of Equipment / Repair

The equipment may be opened only by authorized service personnel to ensure the safe and correct operation of the equipment and to keep the warranty valid.

Even original spare parts may be installed only by authorized service personnel.

In case the equipment was opened by unauthorized personnel, no warranty regarding personal safety, measurement accuracy, conformity with applicable safety measures or any consequential damage is granted by the manufacturer.

Repair and Parts Replacement by Authorized Service Personnel

When the instrument is opened, voltage conducting parts may be exposed. The instrument must be disconnected from the measuring circuit before the performance of repairs or the replacement of parts. If repair of a live open instrument is required, it may only be carried out by trained personnel who are familiar with the dangers involved.

Defects and Extraordinary Strains

If it may be assumed that the instrument can no longer be operated safely, it must be removed from service and secured against unintentional use. Safe operation can no longer be relied upon:

• If the device demonstrates visible damage,

• If the instrument no longer functions, or if malfunctioning occurs,

• After long periods of storage under unfavorable conditions, e.g. humidity, dust or extreme temperature (see “Ambient Conditions” on page 64).

GMC-I Messtechnik GmbH 9

Safety Warnings

1.1 Use for Intended Purpose

• The respective multimeter is a portable device which can be held in the hand during the performance of measurements.

• Only those types of measurements described in chapter 5 may be performed with the measuring instrument.

• The measuring instrument, including measurement cables and plug-on test probes, may only be utilized within the specified measuring category (see page 65 and the table on page 8 regarding significance).

• Overload limits may not be exceeded. See technical data on page 60 for overload values and overload limits.

• Measurements may only be performed under the specified ambient conditions. See page 64 regarding operating temperature range and relative humidity.

• The measuring instrument may only be used in accordance with the specified degree of protection (IP code) (see page 66).

1.2 Meanings of Danger Symbols

Warning concerning a point of danger (attention: observe documentation!)

Warning concerning dangerous voltage at the measurement input: U > 15 V AC or U > 25 V DC

1.3 Meanings of Acoustic Warning Signals

Voltage warning: > 1000 V (intermittent acoustic signal)

Current warning: > 11 A (continuous acoustic signal)

10 GMC-I Messtechnik GmbH

Safety Warnings

GMC-I Messtechnik GmbH 11

Operating Overview – Connections, Keys, Rotary Switch, Symbols

Chap. 3 

Chap. 6

Chap. 4.3

Chap. 3 Chap. 5

Chap. 7

Chap. 6



Chap. 3

ff.

Chap. 3

Chap. 4.1



Chap. 4.1.2

Max. 1000 V!

Chap. 4.1 

Chap. 4.4 

Chap. 6 

Chap. 3.1 

Chap. 1.2

2 Operating Overview – Connections, Keys, Rotary Switch, Symbols

1 Display (LCD) (see page 13 for significance of symbols) 2

MAN / AUTO

 Increase parameter values

shift key for manual/automatic measuring range selection

“Operating Mode” menu:

Selection of individual menu entries against

the direction of flow

ON / OFF | LIGHT

key for switching device and display illumination on and off

4 FUNC | ENTER multifunction key

“Operating Mode” menu: Acknowledge entry (ENTER)

ISO ON / OFF Insulation resistance measurement

Key for switching insulation resistance measurement on and off 5 Increase measuring range or move decimal point to the right (MAN function) 6

Rotary switch

for measuring functions (see page 14 for significance of symbols) 7 DAkkS calibration mark 8 Connector socket for ground / connected to ground 9 Connector socket for current measurement with automatic blocking

10 Connector socket for voltage, resistance, temperature, diode

capacitance measurement

with automatic blocking

11 DATA / MIN / MAX

Key for freezing, comparing, deleting the measured value, and for Min/Max function

 Decrease values

“Operating Mode” menu:

MEASURE | SETUP

Select individual menu entries in flow direction

Key for switching between measuring and menu functions

13 ZERO | ESC

12 GMC-I Messtechnik GmbH

Key for zero balancing “Operating Mode” menu: Exit menu level and return to a higher level, exit

parameters entry function without saving

METRAHIT COIL

only – Function COIL:

UCOIL ON / OFF Interturn short-circuit measurement as long as

key is being pressed, see chapter 5.8. 14 Decrease measuring range or move decimal point to the left (MAN function) 15 Power pack connector jack 16 Infrared interface

and

Symbols used in the Digital Display

Battery full

Battery OK

Battery weak

Battery (almost) dead, U < 1.8 V

Data transmission to / 

from the multimeter is active

IR interface in standby mode (ready to receive starting commands)

Battery level indicator

Interface indicator

1 2910

15 16

765

1921

Operating Overview – Connections, Keys, Rotary Switch, Symbols

1 Battery level indicator 2 ON: continuous operation (automatic shutdown deactivated) 3 MAN: manual measuring range selection active 4 Digital display with decimal point and polarity display 5 max/min: Min/Max value storage 6 DATA: display memory, “freeze measured value” 7 STORE: memory mode active 8 ISO: insulation resistance measurement active / selected test voltage

9 1: x current clip factor (transformation ratio) 10 IR: infrared interface display 11 Scale for analog display 12 Pointer for analog display (bar graph – pointer)

triangle appears: indicates overranging 13 Diode measurement selected 14 Selected type of current 15 TRMS measurement 16 Pt100(0): selected platinum resistance thermometer with

automatic recognition of Pt100/Pt1000 17 Type K: temperature measurement with type K (NiCr-Ni) thermocouple 18 sec (seconds): unit of time 19 REL: relative measurement with reference to offset 20 Unit of measure 21 ZERO: zero balancing active 22 Duty Cycle Measurement

(this function only available with customer-specific variant)

23 Warning regarding dangerous voltage: U > 15 V AC or U > 25 V DC

24 Continuity test with acoustic signal active 25 h (hours): unit of time

GMC-I Messtechnik GmbH 13

Operating Overview – Connections, Keys, Rotary Switch, Symbols

1kHz

VDC+=

Symbols used for Rotary Switch positions

Switch

1M



ISO

COIL/M

V~ 0/5 V~ AC TRMS Alternating voltage, AC TRMS, full bandwidth

Hz (V) 1 Hz ~ AC Voltage frequency, full bandwidth

% 2%

V~ 3 V Fil ~ AC TRMS Voltage frequency, with low pass filter (1 kHz)

Hz (V)

V 0/2 V DC Direct voltage

V 1 V DC AC TRMS Pulsating voltage, TRMS ( )



Temp RT D 0 C Pt 100/1000 Temp TC 1 C Typ-K Temperature with thermoelement type K

A 0/2 A DC Direct current value

A 1 A DC AC TRMS Pulsating current amperage, AC DC TRMS

A~ 0/2 A~ AC TRMS Alternating current amperage, AC TRMS

Hz (A) 1 Hz ~ AC Current frequency

FUNC

Display Measuring Function

0/2 V DC AC TRMS Pulsating voltage, TRMS DC + AC, 15 Hz ... 500 Hz

@UISO

1UISO / kM Insulation resistance measurement



0 UCOIL [μs] Interturn short-circuit measurement with METRAHIT COIL

@UISO

only for detection of interference voltage!

Duty Cycle Measurement

with METRAHIT COIL

4 Hz Fil ~ AC Voltage frequency, with low pass filter (1 kHz)

0  (DC) resistance 0/2  Continuity test with acoustic signal

V DC Diode voltage where I is constant

Temperature with Pt 100 / Pt 1000 resistance thermometer

0nF, F Capacitance

Additional Function clip-on (by menu SET  CLIP 1:1/10/100/1000)

Clip-on AC (V): clip-on current sensor Clip-on Hz (V): clip-on current sensor

Clip-on DC (V): clip-on current sensor Clip-on DC + AC (V): clip-on current sensor

Clip-on AC (A): clip-on current transformer Clip-on Hz (A): clip-on current transformer

14 GMC-I Messtechnik GmbH

User Interface Symbols in the Following Chapters

5 V / 600 mA

Serial number

Registration number Date of calibraion (year – month)

German Accrediation Body GmbH – Calibration lab

XY123

2012-07

D-K-

15080-01-01

 ...  Scroll through main menu

 ...  Scroll through submenu

  Select decimal point

 Increase/decrease value

time Submenu/parameter (7-segment font)

1nFo Main menu (7-segment font, boldface)

Symbols on the Device

Warning concerning a point of danger (attention: observe documentation!)

Ground

Operating Overview – Connections, Keys, Rotary Switch, Symbols

Position of the power pack adapter socket, see also chapter 3.1.

Fuse for current measuring ranges (see chapter 9.3)

The device may not be disposed of with the trash. Further information regarding the WEEE mark can be accessed on the Internet at www.gossenmetrawatt.com under the search term WEEE (see also chapter 9.5).

Calibration mark (blue seal):

CAT II / III Measuring category II or I II device, see also

See also “Recalibration” on page 71.

“Measuring Categories and their Significance per IEC 61010-1” on page 8.

Continuous, doubled or reinforced insulation

Indicates EC conformity

▲

▼

GMC-I Messtechnik GmbH 15

Position of the infrared interface, window on the top of the instrument

Initial Start-Up – Setup

Attention!

Note

3 Initial Start-Up

3.1 Batteries

Be certain to refer to chapter 9.2 regarding correct battery installation!

Momentary battery voltage can be queried in the “Info” menu (see chapter 6.3).

Disconnect the instrument from the measuring circuit before opening the battery compartment lid in order to replace the batteries.

Operation with Power Pack (not included, see chapter 10.3)

Installed batteries are disconnected electronically if the NA X-TRA power pack is used, and need not be removed from the instrument. If rechargeable batteries are used, they must be recharged externally. If the external power supply is switched off, the device is switched to battery operation without interruption.

3.2 Activation

Switching the Instrument On Manually

➭ Press the ON / OFF | LIGHT key until the display appears.

Power-up is acknowledged with a brief acoustic signal. As long as the key is held depressed, all of the segments at the liquid crystal display (LCD) are illuminated. The LCD is depicted on page 13. The instrument is ready for use as soon as the key is released.

Display Illumination

After the instrument has been switched on, background illumination can be activated by briefly pressing the ON / OFF | LIGHT key. Illumination is switched back off by once again pressing the same key, or automatically after approximately 1 minute.

Switching the Instrument On with a PC

The multimeter is switched on after transmission of a data block from the PC, assuming the “irStb” parameter has been set to “ir on” (see chapter 6.4).

However, we recommend using the power saving mode: “ir off”.

Electrical discharge and high frequency interference may cause incorrect displays to appear, and may disable the measuring sequence. Disconnect the device from the measuring circuit. Switch the instrument off and back on again in order to reset. If the problem persists, briefly dislodge the battery from the connector contacts (see also chapter 9.2).

3.3 Setting the Operating Parameters

Setting Time and Date

See “t iME” and “dAtE” parameters in chapter 6.4.

Display Modes for the Digital Display

Selection can be made from two different display modes (see “0.d iSP” parameter in chapter 6.4).

16 GMC-I Messtechnik GmbH

ON / OFF

LIGHT

FUNC

ENTER

ON / OFF

LIGHT

Auto-Range

88.8.8.8

Illumination On

800.00

ON / OFF

LIGHT

Illumination Off

800.00

ON / OFF

LIGHT

0ff

ON / OFF

LIGHT

long (1 s)

3.4 Switching the Instrument Off

Switching the Instrument Off Manually

➭ Press the ON / OFF | LIGHT key until 0FF appears at the display.

Shutdown is acknowledged with a brief acoustic signal.

Automatic Shutdown

The instrument is switched off automatically if the measured value remains unchanged for a long period of time (maximum measured value fluctuation of approximately 0.8% of the measuring range per minute or 1 C or 1 F per minute), and if none of the keys or the rotary switch have been activated before a selected period of time in minutes has elapsed (see “APoFF” parameter on page 53). Shutdown is acknowledged with a brief acoustic signal. Exceptions include: Transmission and memory mode operation, continuous operation and whenever a dangerous voltage is applied to the input (U > 15 V AC or U > 25 V DC).

Disabling Automatic Shutdown

The instrument can be set to continuous operation.

➭ Simultaneously press the

The “Continuous On” function is indicated at by means of the

ON display to the right of the battery symbol.

The “Continuous On (on)” setting can be cancelled by changing the respective parameter or by switching the instrument off manually. In this case the parameter will be reset to 10 min (see “APoFF” on page 56).

and keys to this end.

Initial Start-Up – Setup

GMC-I Messtechnik GmbH 17

Control Functions

4 Control Functions

4.1 Selecting Measuring Functions and Measuring Ranges

4.1.1 Automatic Range Selection

The multimeter is equipped with auto-ranging for all measuring functions, except for temperature measurement, and diode and continuity testing. Auto-ranging is active as soon as the instrument is switched on. The instrument automatically selects the measuring range which allows for highest possible resolution of the applied quantity. When the instrument is switched to frequency measurement, the previously selected voltage measuring range remains active.

AUTO-Range Function

The multimeter is switched automatically to the next higher range at (3099 d + 1 d 0310 d), and to the next lower range at (280 d - 1 d  2799 d).

With high resolution the multimeter is switched automatically to the next higher range at (30999 d + 1 d 03100 d), and to the next lower range at (2800 d - 1 d  27999 d).

4.1.2 Manual Measuring Range Selection

Auto-ranging can be deactivated and measuring ranges can be selected manually in accordance with the following table by pressing the MAN / AUTO button.

The desired measuring range can then be selected with the

 or

 key.

The instrument is automatically returned to range selection when the MAN / AUTO key is pressed, the rotary switch is activated or the instrument is switched off and back on again.

Overview: Auto-Ranging and Manual Range Selection

Function Display

MAN / AUTO

Range switching sequence for:

V: 300 mV* Hz: 300 Hz

:

300

 or 

MAN / AUTO

* Via manual measuring range selection only



300A 3 mA 30 mA 300 mA 3A  10A

A : See chapter 5.9.3 und chapter 5.9.4 F: 30 nF 300 nF 3F 30F 300F M



300 k

@ISO

Return to automatic measuring range selection —

Manual mode active:

utilized measuring range is fixed



3 V 30 V 300 V 1000 V



3 kHz 30 kHz 300 kHz (Hz(U)) 3 k



30 k



300 k



3 M



30 M



300 M

3 M



3000 M

30 M

MAN



MAN



The multimeter is held in the selected measuring range. If the range limit is exceeded, 0L appears at the display. You should then switch to the next higher measuring range with the help of the  key.

18 GMC-I Messtechnik GmbH

Control Functions

Note

4.1.3 Quick Measurements

Measurements performed using a suitable fixed measuring range are executed more quickly than those which utilize automatic range selection. Quick measurement is made possible with the following two functions:

• Manual measuring range selection, i.e. selection of the measuring range with the best resolution (see chapter 4.1.2)

•With the DATA function (see chapter 4.4). In this way, the appropriate measuring range is selected automatically after the first measurement and the second measurement is executed more quickly.

The selected measuring range remains active for the subsequent series of measurements with these two functions.

4.2 Zero Offset / Relative Measurements

Zero balancing or a reference value for relative measurements can be stored to memory depending upon deviation from the zero point:

Deviation from zero – with short-circuited measurement cables for V, , A – with open input for capacitance unit of measure: F

0 to 200 digits ZERO REL

> 200 to 1500 digits REL

Display

The relevant reference or correction value is deducted individually for the respective measuring function as an offset from all future measurements and remains in memory until deleted, or until the multimeter is switched off.

Zero balancing and reference value adjustment can be used for auto-ranging, as well as for manual measuring range selection.

Note: Zero balancing is not possibIe in switch position

M@UISO

Zero Balancing

➭ Plug the measuring cables into the instrument and connect the

free ends to each other, except for capacitance measurement in which case the ends of the cables are not connected to each other.

➭ Briefly press the ZERO | ESC key.

The instrument acknowledges zero balancing with an acoustic signal, and the “ZERO REL” symbol appears at the LCD. The value measured at the moment the key is pressed serves as a reference value.

➭ Zero balancing can be cleared by once again pressing the

ZERO | ESC key.

As a result of TRMS measurement, the multimeter displays a residual value of 1 to 10/35 digits with short-circuited measurement cables as the zero point for V AC / I AC or V(AC+DC) / I (AC+DC) measurements (non-linearity of the TRMS converter). This has no influence on specified accuracy above 1% of the measuring range (or 3% in the mV, V(AC+DC) ranges).

Setting the Reference Value

➭ Plug the measuring cables into the instrument and measure a

reference value (max. 1500 digits).

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Control Functions

➭ Briefly press the ZERO | ESC key.

The instrument acknowledges storage of the reference value with an acoustic signal, and the “ZERO REL” or the “REL” symbol appears at the LCD. The value measured at the moment the key is pressed serves as a reference value.

➭ The reference value can be cleared by once again pressing the

ZERO | ESC key.

Notes Regarding Relative Measurement

• Relative measurement effects the digital display only. The analog display continues to read out the original measured value.

• In the case of relative measurement,  F or AC quantities may also appear as negative values.

4.3 Display (LCD)

4.3.1 Digital Display

4.3.2 Analog Display

Measured Value, Polarity

The analog display demonstrates the dynamic performance of a moving-coil mechanism. This display is especially advantageous for observing measured value fluctuation, and for balancing procedures.

Display mode Pointer: the current measured value is tracked in real-time.

The analog scale displays a negative range of 5 scale divisions for the measurement of zero-frequency quantities, allowing for precise observation of measured value fluctuation around zero. If the measured value exceeds the negative range of 5 scale divisions, polarity is reversed at the analog display.

Scaling of the analog scale is automatic. This is very helpful for manual measuring range selection.

Measured Value, Unit of Measure, Type of Current, Polarity

The measured value with decimal and plus or minus sign appears at the digital display. The selected unit of measure and current type are displayed as well. A minus sign appears to the left of the value during the measurement of zero-frequency quantities, if the

Overranging

Overranging in the positive range is displayed by means of the right triangle symbol.

plus pole of the measured quantity is applied to the “” input. The “0.d iSP” parameter can be used to determine whether lead- ing zeros will be appear or be suppressed at the measured value display (see chapter 6.4).

Refresh Rate

In the bar graph and pointer modes, the analog display is refreshed 40 times per second.

Overranging

If the upper range limit of 3100 digits is exceeded “0L” (overload) appears at the display. Exceptions: “0L” appears at the display as of 1000.0 V in the case of voltage measurement in the 1000 V range, as of 5.100 V for diode testing, and as of 11.00 A in the 10 A range.

20 GMC-I Messtechnik GmbH

Note

V, A, Hz

t [s]

100%

10%

Activated

Reactivated

Save

3000 digits

of Measuring Range

F, %

Control Functions

4.4 Measured Value Storage: DATA (auto-hold / compare)

An individual measured value can be automatically “frozen” with the DATA function (auto-hold). This is useful, for example, when contacting the measuring points with the test probes requires your full attention. After the measuring signal has been applied and the measured value has settled in in accordance with the “condition” listed in the table below, the measured value is frozen at the digital display and an acoustic signal is generated. The test probes can now be removed from the measuring points, and the measured value can be read from the digital display. If the measuring signal falls below the value specified in the table, the function is reactivated for storage of the next value.

Measured Value Comparison (DATA Compare)

If the currently frozen value deviates from the first saved value by less than 100 digits, the acoustic signal is generated twice. If deviation is greater than 100 digits, only one brief acoustic signal is generated.

The DATA function has no effect on the analog display, at which the current measured value continues to appear.

DATA

Function

activate brief blinks once

save (stabilized measured

value)

reactivate

Press

DATA /

Min/Max

However, when the digital display is “frozen”, the decimal point is fixed as well (fixed measuring range, symbol: MAN). The selected measuring range should not be manually changed as long as the DATA function is active.

The DATA function is deactivated by pressing and holding the DATA/MIN/MAX key (approx. 1 second), when the measuring function is changed or when the instrument is switched off and back on again.

GMC-I Messtechnik GmbH 21

change to

Min/Max

exit long

Reactivation results from falling short of specified measured value limits.

Two acoustic signals are generated the first time a measured value is saved as a reference value. For subsequent data hold, two acoustic signals are only generated if the currently frozen value deviates from the than 100 digits.

Key: MV = measured value, R = measuring range

brief See table in chapter 4.4.2

Condition

Measuring

Function

V, A, F, Hz, %> 10%



V, A, F, Hz, %< 10%



Measuring

Signal

of R

0L

of R

= 0L

Response from Instrument

Display

Digital

is displayed

stored

is cleared is cleared

first

saved value by less

DATA

static

blinks

Acou-

stic

once

twice

Control Functions

Example

The voltage measuring range is set manually to 30 V. The first measured value is 5 V and is stored to memory because it is greater than 10% of the measuring range (= 3 V), and is thus reliable above the background noise level. As soon as the measured values drops to less than 10% of the measuring range, i.e. amounts to less than 3 V which corresponds to removal of the test probes from the measuring point, the instrument is ready to store a new value.

4.4.1 Function DATA during insulation measurement *

This DATA function differs from the standard DATA-Compare function.

In the interference voltage measurement function V(ac+dc)1M the special DATA function for insulation measurement is activated by pressing the DATA key – DATA blinks in the display. During inter- ference voltage measurement, no DATA values are determined or stored yet. By briefly pressing the FUNC | ENTER key, the insulation measurement is activated and the test voltage is applied. An intermittent acoustic signal indicates to the user that the test voltage is applied (accompanied by a blinking of the ISO symbol in the display). After applying the test probes, a check is being made as to whether a valid measured value is present. As soon as a stable measured value appears in the display, the DATA value is stored (frozen in the display). A long acoustic signal indicates that the measurement is completed, the test voltage is switched off again, DATA no longer blinks and the user can read and note down the measured value. By repeatedly pressing the FUNC | ENTER key, the test voltage is applied again and DATA is activated (DATA blinks in the display).

If no DATA value is determined or if OL is shown in the display, the test voltage is automatically switched off after approx. 10 seconds. In order to deactivate the DATA function, the FUNC | ENTER key must be pressed and held.

* This function is especially available for variant METRAHIT ISO AERO,

for other variants as from firmware version 1.18.

22 GMC-I Messtechnik GmbH

4.4.2 Saving Minimum and Maximum Values – MIN/MAX Function

Note

Minimum and maximum measured values applied to the measuring instrument’s input after the Min/Max function has been activated can be “frozen” at the display. The most important use of this function is the determination of minimum and maximum values during long-term measured value observation.

The Min/Max function can be activated in all measuring functions. The Min/Max function has no effect on the analog display, at

which the current measured value continues to appear. Apply the measured quantity to the instrument and set the

measuring range with the MAN / AUTO key before activating the Min/Max function.

The Min/Max function is deactivated by pressing and holding the DATA/MIN/MAX key (approx. 1 second), when the measuring function is changed or when the instrument is switched off and back on again.

As opposed to the DATA function, the Min/Max function can also be used for temperature measurement.

Function Min/Max

activate

and save

save and

display

return to 1

stop long are deleted

Press

DATA /

Min/Max

2 x brief are saved

brief

Min. and Max.

Measured Values

storage continues

in background,

new min. and max.

values are displayed.

same as 1,

stored values are not

deleted

Control Functions

Response from Instrument

Display

Measured

Valu e

Digital

current

measured

value

saved min.

value

saved max.

value

same as 1

current

measured

value

Max. Min.

max and min

min.

max.

same

as 1

deleted

Acous-

Signal

tic

twice

once

twice

GMC-I Messtechnik GmbH 23

+ 53 hidden pages

Gossen Metrawatt M246C, METRAHIT COIL User guide

Specifications and Main Features

Frequently Asked Questions

User Manual

1 Safety Features and Precautions

1.1 Use for Intended Purpose

1.2 Meanings of Danger Symbols

1.3 Meanings of Acoustic Warning Signals

2 Operating Overview – Connections, Keys, Rotary Switch, Symbols

3 Initial Start-Up

3.1 Batteries

3.2 Activation

3.3 Setting the Operating Parameters

3.4 Switching the Instrument Off

4 Control Functions

4.1 Selecting Measuring Functions and Measuring Ranges

4.1.1 Automatic Range Selection

4.1.2 Manual Measuring Range Selection

4.1.3 Quick Measurements

4.2 Zero Offset / Relative Measurements

4.3 Display (LCD)

4.3.1 Digital Display

4.3.2 Analog Display

4.4 Measured Value Storage: DATA (auto-hold / compare)

4.4.1 Function DATA during insulation measurement *

4.4.2 Saving Minimum and Maximum Values – MIN/MAX Function