Isotech IDM 91E User manual

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INSTRUCTION MANUAL
IDM91E DIGITAL MULTIMETER
EN FR IT DE JP

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ISO - TECH IDM 91E
DIGITAL MULTIMETER
INSTRUCTION MANUAL

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WARNING
THESE SERVICING INSTRUCTIONS ARE FOR USE BY QUALIFIED PERSONNEL ONLY. TO AVOID
ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING OTHER THAN THAT CONTAINED IN THE
OPERATING INSTRUCTIONS UNLESS YOU ARE QUALIFIED TO DO SO.
TO AVOID ELECTRIC SHOCK, DISCONNECT MEASURING TERMINALS BEFORE OPENING ENCLOSURE.

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INTRODUCTION
1-1 Unpacking and Inspection
Upon removing your new Digital Multimeter from its packing, you should have the following items:
1. Digital Multimeter.
2. Test lead set (one black, one red).
3. Instruction Manual.
4. Protective holster.
1-2 Meter Safety
Terms marked on Equipment
ATTENTION — Refer to Manual.
DOUBLE INSULATION — Protection Class II.
DANGER — Risk of electric shock

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Symbols in this Manual
This symbol indicates where cautionary or other information is found in the manual.
Battery
1-3 Front Panel
Refer to Figure 1 and the following numbered steps to familiarize yourself with the meter's front panel controls and
connectors.
1. Digital Display — The digital display has a 3-1/2 LCD readout (maximum reading 1999) with automatic polarity,
overrange and low battery indicators.
2. Rotary Switch — Select the Function and Range desired.
3. COM Input Terminal — Ground input connector.
4. V Ω:Input Terminal — Positive input connector for Volts, Ohms and Diode.
5. mA µA Input Terminal — Positive input connector for mA and µA measurements (up to 200mA).
6. 10A Input Terminal — Positive input connector for Amp measurements (up to 10A).

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1 2 4 3 5 6
Figure 1

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SPECIFICATIONS
2-1 General Specifications
This instrument has been designed and tested in accordance with IEC Publication 1010 Pt 1, Class II, Safety Re-
quirements for Electrical Equipment for Measurement, Control and Laboratory Use. This level of safety can only be
guaranteed while the limits of section 2.2 are observed.
Display : 3-1/2 digit Liquid Crystal Display (LCD) with a maximum reading of 1999.
Polarity Indication : Automatic, positive implied, negative indicated.
Zero Adjustment : Automatic.
Overrange Indication : "1" or "-1".
Low Battery Indication: "" is displayed when the battery voltage drops below operating voltage.
Measuring Rate: 2.5 times per second, nominal.
Auto Power Off: Approx. 30 minutes.

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2-2 Environmental Conditions:
Maximum Altitude : 2000m
Installation Category : IEC 1010 600V CAT II 300V CAT III.
Pollution Degree : 2
Operating Temperature : 0°C to 50°C, 0 to 80% R.H.
Storage Temperature : -20°C to 60°C, 0 to 80% R.H when battery removed from meter.
Temperature Coefficient : 0.15 x (Specified accuracy) / °C, <18°C or >28°C.
Power Requirements : Alkaline 9V battery, NEDA 1604A, JIS 6AM6, IEC 6LF22.
Battery Life : Alkaline 300 hours.
Dimensions (WxHxD) : 84mm x 175mm x 31mm, without holster
95mm x 192 mm x 50 mm, with holster.
Weight (including battery) : 340 gms, without holster
550 gms, with holster.
Supplied Accessories : Protective Holster, Battery (installed) and Instruction Manual.

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2-3 Electrical Specifications
Accuracy is ± (% reading + number of digits) at 23°C ± 5°C, less than 75% R.H.
(1) DC Volts
Range Resolution Accuracy Over voltage
protection
200mV 100µV
±(0.5%reading + 1digit)
2V 1mV
20V 10mV
200V 100mV
600V 1V
600V d.c. or 600 V a.c. rms
Input Impedance : 10MΩ.

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(2) AC Volts
Range Resolution Accuracy Over voltage
protection
200mV 100 µV
±(1.25%reading + 4digit)
40Hz — 500Hz
2V 1mV
20V 10mV
200V 100mV
600V 1V
600V d.c. or 600 V a.c. rms
Input Impedance : 10MΩ, less than 100pF

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(3) DC Current
Range Resolution Accuracy Voltage Burden
200 µA 0.1 µA
±(1.0%reading + 1digit) 600mV max.
2mA 1 µA
20mA 10 µA
200mA 100 µA
10A 10mA ±(2.0%reading + 3digit) 900mV max.
Overload Protection : 1A/415V fast blow fuse for mA, µA input.
10A/415V fast blow fuse for 10A input.

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(4) AC Current
Range Resolution Accuracy Voltage Burden
200 µA 0.1 µA
±(1.5%reading + 3digit)
40Hz — 500Hz 600mV rms max.
2mA 1 µA
20mA 10 µA
200mA 100 µA
10A 10mA ±(2.5%reading + 3digit)
40Hz — 500Hz 900mV rms max.
Overload Protection : 1A/415V fast blow for mA, µA input.
10A/415V fast blow for 10A input.

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(5) Resistance
Range Resolution Accuracy Max.Test
Current Max.Open Circuit Voltage
200Ω0.1Ω±(0.75%reading + 4digit) 2.5mA 3.2V
2KΩ1Ω
±(0.75%reading + 1digit)
200 µA
20KΩ10Ω40 µA
200KΩ100Ω4 µA
20MΩ10KΩ±(1.5%reading + 5digit) 40nA
0.5V
2MΩ1KΩ400nA
Overload Protection : 500V d.c/a.c max.

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(6) Diode Check
Range Resolution Accuracy Max.Test
Current Max.Open Circuit voltage
 1mV ±(1.5%reading + 5digit) 1.5mA 3.2V
* Overload Protection: 500V d.c/a.c max.
Instant Continuity Description:
Internal sounder operates when resistance is less than 50Ω.
(7) Auto Power Off:
The meter will automatically shut itself off after approximately 30 minutes when the rotary switch is not changed.
The meter can be turned back on by switching to another range.
(8) Sounder Guard
The sounder will operate if the test lead is connected to the mA/µA (10A) input terminal while the rotary function
selector is not in mA/µA (10A) position. There is no sounder guard on the 20mA/10A range of DC and AC function.

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OPERATION
3-1 Preparation and Caution before Measurement
1. Allow at least 60 seconds after switching on before taking measurements.
2. Remove test leads from the circuit under test before changing the measurement range.
3. If the equipment is used near noise generating equipment, be aware that the display may become unstable or
indicate large errors.
3-2 Voltage Measurements
1. Set the rotary switch at the required position.
2. Connect black test lead to "COM" terminal and red lead to "VΩ:" input terminal.
3. Connect test leads to measuring points and read the display value.

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TEST EQUIPMENT RISK ASSESSMENT (UK RECOMMENDATION)
Users of this equipment and/or their employers are reminded that Health and Safety legislation require them to carry
out valid risk assessments of all electrical work so as to identify potential sources of electrical danger and risk of
electrical injury such as from inadvertent short circuits. Where the assessments show that the risk is significant then
the use of fused test leads constructed in accordance with the HSE guidance note GS38 "Electrical Test Equipment
for use by Electricians" should be used.
WARNING
TO AVOID ELECTRIC SHOCK, HAZARD OR DAMAGE TO METER, DO NOT ATTEMPT TO MEASURE
VOLTAGE THAT MIGHT EXCEED 600 V d.c. OR 600V a.c. rms.
DO NOT APPLY MORE THAN 600V d.c. OR a.c. rms BETWEEN THE COMMON INPUT TERMINAL AND EARTH
GROUND. NOTICE
UNSTABLE DISPLAY MAY OCCUR ESPECIALLY AT 300mV RANGE, EVEN IF TEST LEADS ARE NOT CON-
NECTED. IN THIS CASE, IF AN ERRONEOUS READING IS SUSPECTED, SHORT THE "VΩ:" TERMINAL
AND THE "COM" TERMINAL, AND MAKE SURE THE DISPLAY READS ZERO.

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3-3 Current Measurements
1. Set the rotary switch to the required position.
2. Connect black test lead to "COM" terminal.
3. Connect red test lead to "mA/µA" terminal for measurement up to 200mA.
For measuring current between 200mA and 10A, connect test lead to "10A" terminal.
4. Connect test leads to measuring points and read the display value.
3-4 Resistance Measurement
1. Set the rotary switch to the required position.
2. Connect black test lead to "COM" terminal and read lead to "VΩ:" input terminal.
3. Connect test leads to measuring points and read the display value.

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3-5 Diode Check
1. Set the rotary switch to the ":" position.
2. Connect the black test lead to the "COM" terminal and the red test lead to the "VΩ:" input terminal.
3. Connect the test lead to the diode. Normally the forward voltage drop of good silicon diode is shown
between .500V and .900V. If the diode under test is defective, "000" (short circuit) or "1" (non-conductance) is
displayed. Reverse check of diode: If the diode under test is good "1" is displayed. If the diode under test is
defective "000" or other values are displayed.
3-6 Continuity Check by sounder
1. Set the rotary switch at the ":" position.
2. Connect the black test lead to "COM" terminal and the red test lead to "VΩ:" input terminal.
3. Connect test leads to the circuit under test.
4. Built-in sounder operates if the resistance in the circuit under test is below 50Ω.

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MAINTENANCE
To keep the instrument clean, wipe the case with a damp cloth and detergent, do not use abrasives or solvents.
Any adjustment, maintenance and repair of opened instrument with voltage present shall be avoided as far as possible
and, if inevitable, shall be carried out by a skilled person who is aware of the hazard involved.
Whenever it is likely that the protection has been impaired, the instrument shall be made inoperative and be secured
against any unintended operation.
The protection is likely to be impaired if, for example, the apparatus:
— shows visible damage,
— fails to perform the intended measurements,
— has been subjected to prolonged storage under unfavorable conditions,
— has been subjected to severe transport stresses.
CAUTION (refer to user instructions).
Double Square Symbol for Class II product.