HT instruments HT9012 User Manual
ENGLISH
User manual
© Copyright HT ITALIA 2010 Versione EN 1.02 - 13/12/2010
HT9012
Contents:
1 SAFETY PRECAUTIONS AND PROCEDURES ..........................................................2
1.1 Preliminary ........................................................................................................................ 2
1.2 Before use......................................................................................................................... 3
1.3 After use............................................................................................................................ 3
1.4 Measuring (overvoltage) categories definitions................................................................. 3
2 GENERAL DESCRIPTION ...........................................................................................4
2.1 TRMS and Mean Value measuring instruments................................................................ 4
2.2 True Root Mean Square value and crest factor definitions ............................................... 4
3 PREPARATION FOR USE ...........................................................................................5
3.1 Initial.................................................................................................................................. 5
3.2 Power supply..................................................................................................................... 5
3.3 Calibration ......................................................................................................................... 5
3.4 Storage.............................................................................................................................. 5
4 OPERATING INSTRUCTIONS.....................................................................................6
4.1 Instrument description....................................................................................................... 6
4.1.1 Commands description............................................................................................................... 6
4.1.2 Alignment marks ......................................................................................................................... 6
4.2 Function key description.................................................................................................... 7
4.2.1 HOLD key ................................................................................................................................... 7
4.2.2 key ........................................................................................................................................ 7
4.2.3 RANGE key ................................................................................................................................ 7
4.2.4 MAX key ..................................................................................................................................... 7
4.2.5 MODE key .................................................................................................................................. 7
4.3 Functions of rotary switch description ............................................................................... 8
4.3.1 DC Voltage measurement ..........................................................................................................8
4.3.2 AC Voltage measurement ..........................................................................................................9
4.3.3 AC Current measurement......................................................................................................... 10
4.3.4 Resistance measurement......................................................................................................... 11
4.3.5 Continuity test and Diode test................................................................................................... 12
5 MAINTENANCE .........................................................................................................13
5.1 General informations....................................................................................................... 13
5.2 Battery replacement ........................................................................................................ 13
5.3 Cleaning .......................................................................................................................... 13
5.4 End of life ........................................................................................................................ 13
6 TECHNICAL SPECIFICATIONS ................................................................................14
6.1 Characteristics.................................................................................................................14
6.1.1 Safety........................................................................................................................................ 15
6.1.2 General data ............................................................................................................................. 15
6.2 Environmental conditions ................................................................................................ 15
6.2.1 Climatic conditions.................................................................................................................... 15
6.3 Accessories.....................................................................................................................15
6.3.1 Standard accessories ............................................................................................................... 15
7 SERVICE....................................................................................................................16
7.1 Warranty conditions......................................................................................................... 16
7.2 Service ............................................................................................................................ 16
EN - 1
HT9012
1 SAFETY PRECAUTIONS AND PROCEDURES
This clamp complies with IEC/EN61010-1. For your own safety and in order to avoid
damaging the instrument, you’re recommended to keep to the instructions contained in this
manual and read carefully all the notes preceded by the symbol .
Take extreme care for the following conditions while measuring:
• Do not measure voltage or current in humid or wet environment
• Do not use the meter in presence of explosive gas (material), combustible gas
(material), steam or dust
• Insulate yourself from the object to be tested
• Do not touch exposed metal (conductive) parts such as test lead ends, sockets, fixing
objects, circuits, etc
• If you detect anomalies of testing end (metal part) and attachment of the meter such as
breakages, deformations, foreign substances, no display, etc., do not take any
measurement
• Measuring voltage over 20V as it might cause human body electricity conduction
The followings symbols are used:
Caution: refer to the instruction manual. An incorrect use may damage the tester
or its components
High Voltage ranger: electrical shock risk
Double insulated instrument
AC Voltage or Current
DC Voltage
Ground reference
1.1 PRELIMINARY
• This apparatus has been designed for use in an environment of pollution degree 2.
Indoor use
• It measures CURRENT and VOLTAGE on CAT IV 600V to ground plants. For
overvoltage categories please see § 1.4
• You must comply with the usual safety regulations aimed at trotecting you against the
dangerous electric current and protecting the instrument against an incorrect operation
• Only the leads supplied with the instrument guarantee compliance with the safety
standard. They must be in good conditions and they must be replaced, if necessary,
with an identical model
• Do not test or connect to any circuit whose voltage or current exceeds the specified
overload protection
• Do not perform any test at environmental conditions exceeding the limits indicated
• Make sure that the battery are installed correctly
• Before connecting the test probes to the installation, check that the function selector is
positioned on the required measurement
• Make sure that the LCD and the rotate switch show the same as the function desired
EN - 2
HT9012
1.2 BEFORE USE
Always keep to the instructions contained in this manual:
CAUTION
Non compliance with the warnings and/or the instructions may damage the
tester and/or its components or injure the operator.
• Before changing the switch’s position, take off the clamp jaw from the tested conductor
or the electrical circuit in order to avoid any accident
• When the clamp is connected to the circuits to be tested, never touch unused terminals
• When testing resistors, do not add voltage. Although there is a protection circuit,
excessive voltage would cause malfunctioning
• Before measuring current, remove the voltage-resistance test leads
• When measuring current, any strong current near or close to the clamp jaw will affect
the accuracy
• When measuring current, always put the tested conductor in the middle of the clamp
jaw in order to obtain a more accurate reading
• If the reading value or the sign indication remains unchanged during the measurement,
check if the HOLD function is active
1.3 AFTER USE
• Once the measurements are completed, turn the rotary switch to OFF
• If you expect not to use the clamp for a long time, remove the battery
1.4 MEASURING (OVERVOLTAGE) CATEGORIES DEFINITIONS
The norm IEC/EN61010-1: Safety requirements for electrical equipment for measurement,
control and laboratory use, Part 1: General requirements, defines what measuring
category, usually called overvoltage category, is. On § 6.7.4: Measuring circuits, it says:
(OMISSIS)
circuits are divided into the following measurement categories:
• Measurement category IV is for measurements performed at the source of the low-
voltage installation
Examples are electricity meters and measurements on primary overcurrent protection
devices and ripple control units
• Measurement category III is for measurements performed in the building installation
Examples are measurements on distribution boards, circuit breakers, wiring, including
cables, bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and
equipment for industrial use and some other equipment, for example, stationary
motors with permanent connection to fixed installation
• Measurement category II is for measurements performed on circuits directly
connected to the low voltage installation
Examples are measurements on household appliances, portable tools and similar
equipment
• Measurement category I is for measurements performed on circuits not directly
connected to MAINS
Examples are measurements on circuits not derived from MAINS, and specially
protected (internal) MAINS-derived circuits. In the latter case, transient stresses are
variable; for that reason, the norm requires that the transient withstand capability of the
equipment is made known to the user
EN - 3
HT9012
2 GENERAL DESCRIPTION
HT9012 meter can performs the herewith measurements:
• DC and AC voltage
• Detection of AC voltage without contact
• AC current
• Resistance and test continuity
• Diode test
Each parameter can be selected by rotating the 8-positions switch included OFF position.
To abilitate the hold function the HOLD key is available. There are also key to
activate/desactivate the display backlight, the RANGE key for manual selction of
measurement ranges, the MAX key for maximum value measurement of some parameters
and the MODE key for the selection of different features common at the same position of
selector rotation. The selected quantity appears on a high-contrast liquid crystal display
with indication of measurement units and functions. The instrument disposes of an Auto
Power Off function consisting in an automatic switching off 15 minutes after last selector
rotation.
2.1 TRMS AND MEAN VALUE MEASURING INSTRUMENTS
Safety testers for alternate quantities are divided into two big families:
• MEAN VALUE instruments: instruments which measure only the value of the wave at
the fundamental frequency (50 or 60 Hz)
• TRUE ROOT MEAN SQUARE instruments, also defined as TRMS: instruments which
measure the true root mean square value of the quantity under test
In presence of a perfectly sinusoidal wave, both families provide identical results. In
presence of distorted waves, instead, the readings are different. Mean value instruments
provide only the value of the fundamental wave while True RMS instruments provide the
value of the entire wave, including harmonics (within the passband of the instrument).
Accordingly, if the same quantity is measured with both kinds of instruments, the
measured values are identical only if the wave is purely sinusoidal. Should it be distorted,
True RMS instruments provide higher values than medium value instruments.
2.2 TRUE ROOT MEAN SQUARE VALUE AND CREST FACTOR DEFINITIONS
The current effective value is defined as follows: “In an interval of time equivalent to a
period, an alternate current with effective value having an intensity of 1A, by passing on a
resistor, disperses the same energy which would be dispersed in the same period of time
by a direct current having an intensity of 1A”. From this definition comes the numerical
+Tt
0
1
expression: G=
T
The Crest Factor is defined as the ratio between the Peak Value of a signal and its
effective value: CF (G)=
for a purely sinusoidal wave it’s worth 2=1.41. In presence of distortions the Crest Factor
assumes higher values as long as the wave distortion is higher.
2
dttg
)(
∫
t
0
The effective value is indicated as RMS (root mean square).
G
p
. This value varies according to the waveform of the signal,
G
RMS
EN - 4
HT9012
3 PREPARATION FOR USE
3.1 INITIAL
The tester has been checked from a mechanical and electrical point of view before
shipment.
Every care has been taken to make sure that the instrument reaches you in perfect
conditions.
However, it’s advisable to make a rapid check in order to detect eventual damages which
may have occurred in transit. Should this be the case, enter immediately the usual claims
with the carrier.
Make sure that all the accessories listed in § 6.3.1 are contained in the package. In case of
discrepancies contact the dealer.
In case of returning of the tester please keep to the instructions given in § 7.
3.2 POWER SUPPLY
The instrument is battery supplied. One battery 9V IEC 1604 NEDA 6F22 are included in
the package. When battery is low, the symbol “ ” appears on the display. Replace it
immediately, following the instructions given in § 5.2.
The instrument disposes of the Auto Power OFF function (not disable) consisting in an
automatic switching off 15 minutes of idleness.
3.3 CALIBRATION
The tester complies with the technical features listed in this manual. Its performances are
guaranteed for one year.
3.4 STORAGE
In order to guarantee the accuracy of the measurements, after a period of storage in
extreme environmental condition, wait for the necessary time so that the tester returns to
normal measuring conditions (see environmental specifications, § 6.2.1).
EN - 5
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