ENGLISH User manual Copyright HT ITALIA 2010 Release EN 1.
HT21 Table of Content: 1. SAFETY PRECAUTIONS AND PROCEDURES .......................................................... 2 1.1. 1.2. 1.3. 1.4. 2. 3. GENERAL DESCRIPTION ........................................................................................... 4 PREPARATION FOR USE ........................................................................................... 4 3.1. 3.2. 3.3. 3.4. 4. Preliminary .................................................................................................
HT21 1. SAFETY PRECAUTIONS AND PROCEDURES This meter is compliance with safety Standard IEC/EN61010-1 related to electronic measuring instruments. For your own safety and to avoid damaging the instrument follow the procedures described in this instruction manual and read carefully all notes preceded by this symbol .
HT21 1.2. DURING USE Read the recommendations which follow and the instructions in this manual: CAUTION An improper use may damage the instrument and/or its components or injure the operator. When changing the range, first disconnect the test leads from the circuit under test in order to avoid any accident When the instrument is connected to measuring circuits never touch any unused terminal When measuring resistors do not add any voltage.
HT21 2. GENERAL DESCRIPTION The HT21 meter performs, in completely Autorange, the herewith measurements: DC Voltage AC sine voltage Resistance and Continuity test Capacitance Frequency Duty cycle Diode test All selectable by means of a 5 position rotary selector (including OFF position).
HT21 4. OPERATING INSTRUCTIONS 4.1. INSTRUMENT DESCRIPTION 4.1.1. Front panel description LEGEND: 1. LCD 2. Rotary selector 3. COM input jack CAP input jack 4. VHz% 5. MODE key 6. Hz% key 7. HOLD/ key 8. REL key 9. Battery cover Fig.
HT21 4.2. DESCRIPTION OF FUNCTION KEYS 4.2.1. HOLD/ key By pressing HOLD/ key the measured value is frozen on the display where the symbol "HOLD" appears. Pressing again HOLD to disable this function and resume normal operation. By pressing the key at least 1 second the enable/disable of backlight feature can be performed. This feature is active for any position of rotary selector. 4.2.2.
HT21 4.3. MEASUREMENTS 4.3.1. DC Voltage measurement CAUTION The maximum input for DC voltage is 600V. Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument. Fig. 2: Using the meter for DC voltage measurement 1. Switch on . “DC” symbol is displayed 2. Insert the test leads into the jacks, the red plug into VHz% CAP jack and black plug into COM jack (see Fig. 2) 3.
HT21 4.3.2. AC Voltage measurement CAUTION The maximum input for AC voltage is 600V. Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument. Fig. 3: Using the instrument for AC voltage measurement 1. Switch on Hz%. “AC” symbol is displayed 2. Insert the test leads into the jacks, the red plug into VHz% CAP jack and black plug into COM jack (see Fig. 3) 3. Connect the test leads to the circuit under test; the voltage value is displayed 4. If the message "O.
HT21 4.3.3. Resistance and Continuity Test measurements CAUTION Before taking resistance measurements in circuit remove power from the circuit being tested and discharge all capacitors. Fig. 4: Using the instrument for resistance and continuity test measurements 1. Switch on CAP. “” symbol is displayed 2. Insert the test leads into the jacks, the red plug into VHz% CAP jack and black plug into COM jack (see Fig. 4) 3. Connect the test leads to the circuit under test.
HT21 4.3.4. Diode test CAUTION Before taking diode test measurements in circuit remove power from the circuit being tested and discharge all capacitors. Fig. 5: Using the instrument for diode test 1. Switch on CAP 2. Pressing the MODE key until the symbol is shown at display to meaning the diode test 3. Insert the test leads into the jacks, the red plug into VHz% CAP jack and black plug into COM jack (see Fig. 5) 4.
HT21 4.3.5. Frequency and Duty Cycle measurements CAUTION The maximum input for AC voltage is 250V. Do not attempt to measure higher voltages to avoid electrical shocks or damages to the instrument. Fig. 6: Using the instrument for frequency and duty cycle measurements 1. Switch on Hz%. “Hz” symbol is displayed 2. Insert the test leads into the jacks, the red plug into VHz% CAP jack and black plug into COM jack (see Fig. 6) 3. Connect the test leads to the circuit under test.
HT21 4.3.6. Capacitance measurement CAUTION Before taking capacitance measurement in circuit remove power from the circuit being tested and discharge all capacitors. Connect the test capacitor to the inputs respecting the polarity connections when required. Fig. 7: Using the instrument for capacitance measurement 1. Switch on CAP 2. Pressing the MODE key until the “nF” symbol is shown at display to meaning the capacitance measurement 3.
HT21 5. MAINTENANCE 5.1. GENERAL INFORMATION This is a precision instrument. To guarantee its performances be sure to use it according to these instructions and keep it stored on suitable environmental conditions. Do not expose it to high temperatures or humidity or direct sunlight. Be sure to turn it off after use. If you expect not to use the instrument for a long period remove batteries to avoid leakages of battery liquid which could damage the its inner components. 5.2.
HT21 6. TECHNICAL SPECIFICATIONS 6.1. TECHNICAL FEATURES The accuracy is calculated as [%reading + (number of digits)*resolution]. It is referred to the following environmental conditions: temperature 18°C28°C (64°F82°F), <70%RH DC Voltage (Autorange) Range 4.000V 40.00V 400.0V 600V Resolution 0.001V 0.01V 0.1V 1V Accuracy Input impedance Overload protection 7.8M 600VDC/ACrms Input impedance Overload protection 7.8M 600VDC/ACrms (1.2%rdg+2dgt) (1.
HT21 Duty cycle (Autorange) Range 0.1%-99% Resolution 0.1% Accuracy (1.2%rdg + 2dgt) Sensibilità >8Vrms Overload protection 250VDC/ACrms 100s< pulse width <100ms ; Frequency range: 5Hz 150kHz Capacitance (Autorange) Range 40.00nF 400.0nF 4.000F 40.00F 100.0F Resolution 0.01nF 0.1nF 0.001F 0.01F 0.1F Accuracy (5.0%rdg + 7dgt) Overload protection (3.0%rdg + 5dgt) 250VDC/ACrms (5.0%rdg +5dgt) 6.1.1.
HT21 7. SERVICE 7.1. WARRANTY CONDITIONS This instrument is guaranteed against material or production defects, in accordance with our general sales conditions. During the warranty period the manufacturer reserves the right to decide either to repair or replace the product. Should you need for any reason to return back the instrument for repair or replacement take prior agreements with the local distributor from whom you bought it.
