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HT401
User Manual
24 pgs639.51 Kb0
User guide [de]
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HT instruments HT401 User Manual

ENGLISH
User manual
Copyright HT ITALIA 2012 Release EN 1.01 - 14/05/2012
HT401
Table of contents:
1.1. Preliminary instructions ..................................................................................................... 2
1.2. During use ......................................................................................................................... 3
1.3. After use ............................................................................................................................ 3
1.4. Definition of measurement (overvoltage) category ............................................................ 3
2.1. Measuring average values and TRMS values ................................................................... 4
2.2. Definition of true root mean square value and crest factor ................................................ 4
3.1. Initial checks ...................................................................................................................... 5
3.2. Instrument power supply ................................................................................................... 5
3.3. Calibration ......................................................................................................................... 5
3.4. Storage .............................................................................................................................. 5
4.1. Instrument description ....................................................................................................... 6
4.1.1. Description of the controls ................................................................................................................. 6
4.2. Description of function keys .............................................................................................. 7
4.2.1. RANGE key ....................................................................................................................................... 7
4.2.2. VoltSense key .................................................................................................................................... 7
4.2.3. MIN MAX key ..................................................................................................................................... 7
4.2.4. SMART HOLD key ............................................................................................................................. 7
4.2.5. Backlight key ............................................................................................................................... 7
4.2.6. MODE key ......................................................................................................................................... 7
4.3. Internal modes of instrument ............................................................................................. 8
4.3.1. PEAK/HOLD mode ............................................................................................................................ 8
4.3.2. AC+DC mode ..................................................................................................................................... 8
4.3.3. AutoV LoZ mode ................................................................................................................................ 8
4.3.4. Disabling the Auto Power OFF function ............................................................................................. 8
4.3.5. Wrong insertion indication ................................................................................................................. 8
4.4. Operating instructions ....................................................................................................... 9
4.4.1. DC Voltage measurement ................................................................................................................. 9
4.4.2. AC Voltage measurement and Frequency ....................................................................................... 10
4.4.3. AC Voltage measurement with low input impedance ...................................................................... 11
4.4.4. DC Current measurement ................................................................................................................ 12
4.4.5. AC Current measurement and Frequency ....................................................................................... 13
4.4.6. Resistance measurement ................................................................................................................ 14
4.4.7. Diode and Continuity test ................................................................................................................. 15
4.4.8. Capacitance measurement .............................................................................................................. 16
4.4.9. Temperature measurement ............................................................................................................. 17
5.1. Battery and fuses replacement ........................................................................................ 18
5.2. Cleaning the instrument .................................................................................................. 18
5.3. End of life ........................................................................................................................ 18
6.1. Technical characteristics ................................................................................................. 19
6.1.1. Electrical characteristics .................................................................................................................. 21
6.1.2. Reference standards ....................................................................................................................... 21
6.1.3. General characteristics .................................................................................................................... 21
6.2. Environment .................................................................................................................... 22
6.2.1. Environmental conditions for use ..................................................................................................... 22
6.3. Accessories ..................................................................................................................... 22
6.3.1. Standard accessories ...................................................................................................................... 22
6.3.2. Optional accessories ....................................................................................................................... 22
7.1. Warranty conditions ......................................................................................................... 23
7.2. Service ............................................................................................................................ 23
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HT401
1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with Directive IEC/EN 61010-1 relevant to electronic measuring instruments. For your safety and in order to prevent damaging the instrument, please carefully follow the procedures described in this manual and read all
notes preceded by the symbol with the utmost attention. Before and after carrying out the measurements, carefully observe the following instructions:
Do not carry out any measurement in humid environments. Do not carry out any measurements in case gas, explosive materials or flammables are
present, or in dusty environments.
Avoid any contact with the circuit being measured if no measurements are being
carried out.
Avoid any contact with exposed metal parts, with unused measuring probes, circuits,
etc.
Do not carry out any measurement in case you find anomalies in the instrument such
as deformation, breaks, substance leaks, absence of display on the screen, etc.
Use extreme care when voltage exceeds 20V. This kind of voltage can cause electric
shock
The following symbols are used in this manual:
CAUTION: observe the instructions given in this manual; improper use could damage the instrument or its components.
High voltage danger: electrical shock hazard.
Double-insulated meter.
AC voltage or current. DC voltage or current.
Ground reference
1.1. PRELIMINARY INSTRUCTIONS
This instrument has been designed for use in environments of pollution degree 2 It can be used for VOLTAGE and CURRENT measurements on installations with
overvoltage CAT III 1000V and CAT IV 600V
Please take the standard safety precautions aimed at protecting you against dangerous
electrical currents and protecting the instrument against incorrect use
Only the leads supplied with the instrument guarantee compliance with the safety
standards. They must be in good conditions and be replaced with identical models, when necessary
Do not test circuits exceeding the specified voltage limits Do not perform any test under environmental conditions exceeding the limits indicated
in § 6.2.1.
Check that the battery is correctly inserted Before connecting the test leads to the circuit to be test ed, make sure that the switch is
correctly set.
Make sure that the LCD display and the rotary switch indicate the same function.
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HT401
1.2. DURING USE
Please carefully read the following recommendations and instructions:
CAUTION
Failure to comply with the Caution notes and/or Instructions may damage the instrument and/or its components or be a source of danger for the operator.
Before activating the rotary switch, disconnect the test leads from the circuit under test. When the instrument is connected to the circuit under test, do not touch any unused
terminal.
Avoid measuring resistance if external voltages are present. Even if the instrument is
protected, excessive voltage could cause a malfunction of the instrument.
While measuring, if the value or the sign of the quantity being measured remain
unchanged, check if the HOLD function is enabled.
1.3. AFTER USE
When measurement is complete, set the rotary switch to OFF to turn off the instrument If the instrument is not to be used for a long time, remove the battery
1.4. DEFINITION OF MEASUREMENT (OVERVOLTAGE) CATEGORY
Standard “IEC/EN61010-1: Safety requirements for electrical equipment for measurement, control and laboratory use, Part 1: General requirements” defines what measurement category, commonly called overvoltage category, is. § 6.7.4: Measured circuits, reads:
(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 on installations inside
buildings.
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 standard requires that the transient withstand capability of the equipment is made known to the user.
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HT401
2. GENERAL DESCRIPTION
The instrument HT401 carries out the following measurements:
DC and AC TRMS voltage DC and AC TRMS current Resistance and Continuity test Frequency of voltage and current Capacitance Diode test Temperature with type K probe DC/AC voltage measurement with low impedance (AutoV)
Each of these functions can be selected using the 10-position rotary switch, including an OFF position. The instrument is also equipped with function keys (see § 4.2) a bargraph and backlight. The selected quantity appears on the LCD display with the indication of the measuring unit and of the enabled functions. The instrument is also equipped with an Auto Power OFF function which automatically switches off the instrument approx. 20 minutes after the last time a function key was pressed or the rotary switch was turned. To switch on the instrument again, turn the rotary switch.
2.1. MEASURING AVERAGE VALUES AND TRMS VALUES
Measuring instruments of alternating quantities are divided into two big families: AVERAGE-VALUE meters: instruments measuring the value of the sole wave at
fundamental frequency (50 or 60 Hz).
TRMS (True Root Mean Square) VALUE meters: instruments measuring the TRMS
value of the quantity being tested. In the presence of a perfectly sinusoidal wave, the two families of instruments provide identical results. In the presence of distorted waves, instead, the rdg shall differ. Average­value meters provide the RMS value of the sole fundamental wave; TRSM meters, instead, provide the RMS value of the whole wave, including harmonics (within the instrument’s bandwidth). Therefore, by measuring the same quantity with instruments from both families, the values obtained are identical only if the wave is perfectly sinusoidal. In case it is distorted, TRMS meters shall provide higher values than the values read by average-value meters.
2.2. DEFINITION OF TRUE ROOT MEAN SQUARE VALUE AND CREST FACTOR
The root mean square value of current is defined as follows: “In a time equal to a period, an alternating current with a root mean square value with an intensity of 1A, circulating on a resistor, dissipates the same energy that, during the same time, would have been dissipated by a direct current with an intensity of 1A”. This definition results in the numeric
expression:
Tt
0
1
2
dttg
G=
T
The Crest Factor is defined as the relationship between the Peak Value of a signal and its RMS value: CF (G)=
sinusoidal wave it is 2=1.41. In case of distortion, the Crest Factor takes higher values as wave distortion increases.
)(
t
0
The root mean square value is indicated with the acronym RMS.
G
p
This value changes with the signal waveform, for a purely
G
RMS
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HT401
3. PREPARATION FOR USE
3.1. INITIAL CHECKS
Before shipping, the instrument has been checked from an electric as well as mechanical point of view. All possible precautions have been taken so that the instrument is delivered undamaged.
However, we recommend generally checking the instrument in order to detect possible damage suffered during transport. In case anomalies are found, immediately contact the forwarding agent.
We also recommend checking that the packaging contains all components indicated in §
6.3. In case of discrepancy, please contact the Dealer. In case the instrument should be replaced, please carefully follow the instructions given in
§ 7.
3.2. INSTRUMENT POWER SUPPLY
The instrument is powered by a single 9V battery type NEDA1604, JIS006P, IEC6F22 included in the package.
In order to prevent compromising its charge, the battery is not inserted in the instrument. For battery installation, follow the instructions given in § 5.1.
The “ ” symbol appears when the battery is flat. Replace the battery by following the instructions given in § 5.2.
3.3. CALIBRATION
The instrument has the technical specifications described in this manual. The instrument’s performance is guaranteed for one year.
3.4. STORAGE
In order to guarantee precise measurement, after a long storage time under extreme environmental conditions, wait for the instrument to come back to normal condition (see the environmental specifications contained in § 6.2.1 before use).
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HT401
4. OPERATING INSTRUCTIONS
4.1. INSTRUMENT DESCRIPTION
4.1.1. Description of the controls
CAPTION:
1. LCD display
2. Function keys
3. MODE key
4. Rotary switch
5. Input terminal A
6. Input terminal mA
7. Input terminal for measuring V .
8. Input terminal COM
Fig. 1: Instrument description
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HT401
4.2. DESCRIPTION OF FUNCTION KEYS
The following § describes the functions of the different keys. When pressing a key, the display shows the symbol of the activated function and the buzzer sounds.
4.2.1. RANGE key
Press the RANGE key to activate the manual mode and to disable the Autorange function. The symbol “RANGE” appears in the upper left part of the display. In manual mode, cyclically press the RANGE key to change measuring range: the relevant decimal point will change position. The RANGE key is not active in the switch position / . In Autorange mode, the instrument selects the most appropriate ratio for carrying out the measurement. If a rdg is higher than the maximum measurable value, the indication “O.L” appears on the display. Press and hold the RANGE key for more than 1 second to exit the manual mode and restore the Autorange mode.
4.2.2. VoltSense key
The VoltSense key permits the detection of AC voltage without contact. Perform the herewith steps:
1. Switch on the instrument in any position of selector
2. Approach the instrument close to the point of test
3. Press and hold the VoltSense key. If an AC voltage is detected a continuous sound is emitted by the instrument and the number of LCD segments indicates the intensity of electric field in the point of test. In case of no indication from the instrument a voltage could be present
4. Release the VoltSense key to exit from the function
4.2.3. MIN MAX key
Pressing the MIN MAX key once activates the detection of maximum and minimum values of the quantity being tested. Both values are constantly updated and are displayed cyclically every time the same key is pressed again. The display shows the symbol associated with the selected function: “MAX” for maximum value and “MIN” for minimum value. The flashing symbol “MAX MIN” shows the current value on the display. The MAX MIN key is not active when the HOLD function is activated. Press and hold the MIN MAX key for more than 1 second or turn the selector to exit the function.
4.2.4. SMART HOLD key
Pressing the SMART HOLD key keeps the value of the measured quantity on the dis play. The symbol “HOLD” appears on the display, the instrument emits a continuous acoustic alarm and the display flashes if the measured value differs by more than 50 dgt from the value read on the display. Press the SMART HOLD key again or turn the rotary switch to exit the function.
4.2.5. Backlight key
Press the key to activate/deactivate the backlight of the display. This function is active in any position of the rotary switch.
4.2.6. MODE key
Press the MODE key to activate the secondary functions (orange-coloured on the switch). Pressing the key again takes the instrument back to primary (initial) functions.
EN - 7
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