HT HT64 User manual

Copyright HT ITALIA 2017 Version EN 2.00 - 29/11/2017
ENGLISH
User manual

HT64
EN - 1
Table of contents:
1.PRECAUTIONS AND SAFETY MEASURES...............................................................2
1.1.Preliminary instructions..................................................................................................... 2
1.2.During use......................................................................................................................... 3
1.3.After use............................................................................................................................ 3
1.4.Definition of Measurement (Overvoltage) category........................................................... 3
2.GENERAL DESCRIPTION...........................................................................................4
2.1.Measuring average values andTRMS values.................................................................... 4
2.2.Definition of true root mean square value and Crest factor............................................... 4
3.PREPARATION FOR USE...........................................................................................5
3.1.Initial checks...................................................................................................................... 5
3.2.Instrument power supply................................................................................................... 5
3.3.Storage.............................................................................................................................. 5
4.NOMENCLATURE........................................................................................................6
4.1.Description of the instrument............................................................................................. 6
4.2.Description of function keys .............................................................................................. 7
4.2.1.HOLD/REL key........................................................................................................................... 7
4.2.2.RANGE key ................................................................................................................................ 7
4.2.3.Function keys F1, F2, F3, F4...................................................................................................... 7
4.2.4.LoZ feature ................................................................................................................................. 7
4.2.5.LEAD message at display .......................................................................................................... 7
4.3.Description of internal functions........................................................................................ 8
4.3.1.Description of the display ........................................................................................................... 8
4.3.2.AC+DC Voltage and Current measurement............................................................................... 8
4.3.3.HOLD function and saving.......................................................................................................... 8
4.3.4.Relative measurement................................................................................................................ 9
4.3.5.Saving MIN/MAX/AVERAGE and PEAK values......................................................................... 9
4.3.6.Creating and saving graphs of measurements......................................................................... 10
4.3.7.Instrument general menu.......................................................................................................... 10
5.OPERATING INSTRUCTIONS...................................................................................17
5.1.DC, AC+DC Voltage measurement................................................................................. 17
5.2.AC Voltage measurement............................................................................................... 18
5.3.AC/DC Voltage measurement with low impedance (LoZ)............................................... 19
5.4.Frequency and Duty Cycle measurement....................................................................... 20
5.5.Resistance measurement and continuity test.................................................................. 21
5.6.Diode test........................................................................................................................ 22
5.7.Capacitance measurement ............................................................................................. 23
5.8.Temperature measurement with K-type probe................................................................ 24
5.9.DC, AC+DC Current measurement and e 4-20mA% reading......................................... 25
5.10.AC Current measurement ............................................................................................... 26
5.11.DC, AC, AC+DC Current measurement with transducer clamps.................................... 27
6.MAINTENANCE .........................................................................................................28
6.1.Recharging the internal battery....................................................................................... 28
6.2.Replacement of internal fuses......................................................................................... 29
6.3.Cleaning the instrument .................................................................................................. 29
6.4.End of life ........................................................................................................................ 29
7.TECHNICAL SPECIFICATIONS ................................................................................30
7.1.Technical characteristics................................................................................................. 30
7.1.1.Reference standards................................................................................................................ 32
7.1.2.General characteristics............................................................................................................. 33
7.1.3.Environmental conditions for use ............................................................................................. 33
7.2.Accessories..................................................................................................................... 33
7.2.1.Accessories provided ............................................................................................................... 33
7.2.2.Optional accessories................................................................................................................ 33
8.ASSISTANCE.............................................................................................................34
8.1.Warranty conditions......................................................................................................... 34
8.2.Assistance....................................................................................................................... 34

HT64
EN - 2
1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with directive IEC/EN61010-1 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 symbol with the utmost attention.
Before and after carrying out 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.
Pay special attention when measuring voltages higher than 20V, since a risk of
electrical shock exists.
In this manual, and on the instrument, the following symbols are used:
Warning: observe the instructions given in this manual; improper use could
damage the instrument or its components.
Double-insulated meter
AC voltage or current
DC voltage or current
Connection to earth
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 CAT
IV 600V and CAT III 1000V.
We recommend following the normal safety rules devised by the procedures for
carrying out operations on live systems and using the prescribed PPE to protect the
user against dangerous currents and the instrument against incorrect use.
In case the lack of indication of the presence of voltage may represent a danger for the
operator, always carry out a continuity measurement before carrying out the
measurement on the live system, in order to confirm the correct connection and
condition of the leads.
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.
Make sure that the LCD display and the rotary switch indicate the same function.

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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 being
measured.
When the instrument is connected to the circuit being measured, do not touch any
unused terminal.
Do not measure resistance in case external voltages are present; even if the
instrument is protected, an excessive voltage may cause malfunction.
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 switch off the
instrument.
If the instrument is not to be used for a long time, remove the batteries.
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.

HT64
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2. GENERAL DESCRIPTION
The instrument carries out the following measurements:
DC/AC/AC+DC TRMS Voltage
DC/AC voltage with low impedance (LoZ)
DC/AC/AC+DC TRMS Current
DC/AC/AC+DC TRMS Current with transducer clamps
AC, AC+DC TRMS current
4-20mA% display
Resistance and Continuity test
Diode test
Capacity
Frequency
Duty Cycle
Temperature with K-type probe
Data Logger function and display of graphs of measured data
Each of these functions can be selected by means of the appropriate switch. The
instrument is also equipped with function keys (see § 4.2), analogue bargraph and LCD
TFT high-contrast color display. The instrument is also equipped with an Auto Power OFF
function which automatically switches off the instrument after a certain (programmable)
idling time.
2.1. MEASURING AVERAGE VALUES ANDTRMS 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.
With a perfectly sinusoidal wave, the two families of instruments provide identical results.
With distorted waves, instead, the readings shall differ. Average-value 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 instruments 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 of 1A intensity, circulating on a
resistor, dissipates the same energy that, during the same time, would be dissipated by a
direct current with an intensity of 1A". This definition results in the numeric expression:
G= 
Tt
t
dttg
T
0
0
)(
12The root mean square value is indicated with the acronym RMS.
The Crest Factor is defined as the relationship between the Peak Value of a signal and its
RMS value: CF (G)= RMS
p
G
GThis value changes with the signal waveform, for a purely
sinusoidal wave it is 2=1.41. In case of distortion, the Crest Factor takes higher values
as wave distortion increases.

HT64
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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 §
6.3.1. In case of discrepancy, please contact the Dealer.
In case the instrument should be returned, please follow the instructions given in § 7.
3.2. INSTRUMENT POWER SUPPLY
The instrument is powered by 1x7.4V rechargeable Li-ION battery included in the
package. When the battery is flat, the symbol “” appears on the display. For battery
recharge, please refer to § 6.1.
3.3. STORAGE
In order to guarantee precise measurement, after a long storage time, wait for the
instrument to come back to normal condition (see § 7.1.3).

HT64
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4. NOMENCLATURE
4.1. DESCRIPTION OF THE INSTRUMENT
CAPTION:
1. LCD display
2. Function key F2
3. Function key F3
4. Function key F1
5. Function key F4
6. RANGE key
7. HOLD/REL key
8. Rotary selector switch
9. Input terminal 10A
10.Input terminal
Hz% V
11.Input terminal mAA
12.Input terminal COM
Fig. 1: Description of the instrument

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4.2. DESCRIPTION OF FUNCTION KEYS
4.2.1. HOLD/REL key
Pressing the HOLD/REL key freezes the value of the measured quantity on the display.
After pressing this key, the message “Hold” appears on the display. Press the HOLD/REL
key again to exit the function. To save the vale on the display, see § 4.3.3.
Press and hold the HOLD/REL key for a long time in order to activate/deactivate relative
measurement. The instrument zeroes the display and saves the displayed value as a
reference value which subsequent measurements will be referred to (see § 4.3.4). The
symbol “” appears on the display. This function is not active in position . Press and
hold the HOLD/REL key again to exit the function.
4.2.2. RANGE key
Press the RANGE key to activate the manual mode and to disable the Autorange function.
The message “Manual” appears on the upper left part of the display instead of “AUTO”. In
manual mode, press the RANGE key to change measuring range: the relevant decimal
point will change its position. The RANGE key is not active in positions ,, Hz%,
°C°F, mV , 10A and 4-20mA %. In Autorange mode, the instrument selects the
most appropriate ratio for carrying out measurement. If a reading 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.
4.2.3. Function keys F1, F2, F3, F4
Use keys F1, F2, F3 and F4 to manage the instrument’s internal functions (see § 4.3).
4.2.4. LoZ feature
This mode permits to perform the AC/DC voltage measurement with a low input
impedance in way to avoid the wrong readings due to stray voltage in capacitive coupled.
CAUTION
Inserting the instrument between phase and ground conductors, the RCDs
protection devices can be tripping out during the test. For phase-PE voltage
measurement after a RCD device preliminarily connect the test leads
between phase and neutral cables at least for 5s, then perform the phase-
PE measurement to avoid unexpected trips-out
4.2.5. LEAD message at display
From instrument switch off (OFF), in the 10A , µA and mA positions a short sound
is emitted and a “LEAD” message is shown for a while to indicate an advise of using test
leads for the current measurements.

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4.3. DESCRIPTION OF INTERNAL FUNCTIONS
4.3.1. Description of the display
CAPTION:
1. Indication of
Automatic/Manual mode
2. Indication of the system's
time
3. Indication of battery charge
level and
activation/deactivation of key
tone (not associated with
continuity test)
4. Indication of measuring unit
5. Indication of measuring result
6. Analogue bargraph
7. Indications associated with
function keys F1, F2, F3, F4
Fig. 2: Description of the display
4.3.2. AC+DC Voltage and Current measurement
The instrument is capable of measuring a possible presence of overlapping alternating
components on a generic voltage or current direct waveform. This can be useful when
measuring typical impulsive signals of non-linear loads (e.g. welding machines, electric
ovens, etc.).
1. Select position VHz%, 10A , mA , A or
2. Press the F2 key selecting the ““ ” or “ ” modes (see Fig. 3)
3. Follow the instructions shown in § 5.1 or § 5.9
Fig. 3: AC+DC voltage or current measurement description
4.3.3. HOLD function and saving
Fig. 4: Saving the value frozen on the display
1. Press the HOLD/REL key again to freeze the result. The message “Hold” appears on
the display.
2. Press the F3 key to save the data in the instrument's memory.
3. Enter the General menu to display the saved result (see § 4.3.7)

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4.3.4. Relative measurement
Fig. 5: Relative measurement
1. Press and hold the HOLD/REL key to enter relative measurement (see Fig. 5 – right
side). The message “REL” and symbol “” appear on the display.
2. Press the F4 key to enter the General menu, save the measured result and display it
(see § 4.3.7).
4.3.5. Saving MIN/MAX/AVERAGE and PEAK values
Fig. 6: Saving MIN/MAX/AVERAGE values
1. Press the F4 key to enter the measuring mode of MAX, MIN and Average values of the
quantity to be measured (see Fig. 6 – central part). The message “MAX MIN” appears
on the display.
2. The values are automatically updated by the instrument, which emits a short beep
whenever the actually displayed values are exceeded (higher for MAX value, lower for
MIN value).
3. Press the F2 key to stop detecting the values and the F1 key to start measuring again.
4. Press the F3 key to save the measured result (see Fig. 6 – right side) and display it
(see § 4.3.7).
Fig. 7: Saving PEAK values
5. Press the F4 key to enter the measuring mode of Peak values of the quantity to be
measured (see Fig. 7 – right side). The message “PEAK” appears on the display and
the values are updated in the same way as for the MAX/MIN function.
6. Press the F2 key to stop detecting the values and the F1 key to start measuring again.
7. Press the F3 key to save the result and display it (see § 4.3.7).