SANWA GENERAL CATALOG - Sanwa Electric Instrument - #26

Safety

Function marks and terminology used in SaflüJä General Catalog

The IEC standard classifies measuring circuits according to measure­ment categories for the safe use of a measuring instrument in low vol­tage facilities. The measurement categories are classified into I to IV. A larger number of the category denotes a spot involving higher tran­sient energy. For safe measurement, wear protective gears such as insulated gloves and dust-proof glasses in an environment of CAT. Ill. Measurement category IV (CAT. IV) : Equipment used for measurement in low voltage facilities. Temporary overcurrent preventer, and electric measurement on rip­ple control unit, etc.

Equipment used for measurement in building facilities Distribution board, circuit breaker, wiring including cables, busbar, junction box, switch, receptacle, and industrial equipment located in fixed facilities, and other equipment such as a fixed motor connected to fixed facilities in a permanent manner. Measurement category II (CAT. II):

Equipment used for measurement performed on a circuit directly con­nected to low voltage facilities

Measurement on electric household appliances, portable tools and similar tools

Equipment used for measurement on a circuit not directly connected to main power supply

Circuit not derived from the main power supply

This Safety Standard which is established for protecting operators and environment stipulates safety requirements for measuring in­struments and electric equipment. The IEC standard defines the degree of pollution, measurement classification, barrier, material, spatial distance and creepage distance to assure safety. The im­pulse withstand voltage as transitional energy is estimated from the measurement category and main power supply voltage to con­duct tests for measuring instruments.

BQCI Zero-center meter (NULL) ■vnfl Moves the indicator of the KAHB analog tester to the center of the scale (meter graduations) to make measurement of positive and negative voltage.

Both ACA and DCAare measurable.

Correctness. JIS defines the term "accuracy" to be used for digital tes­ters and "tolerance" for analog tes­ters. The accuracy / tolerance differs depending on the range.

■ ± (□%+□) =± (□%rdg+Ddgt) rdg is an abbreviation of "Reading" meaning a read value on digital dis­play, "dgt" is an abbreviation of "Digit" meaning the least unit of digital dis­play. For instance, "±2dgt" refers to error of ±2 counts.

It is the indication of tolerance ex­pressed by percentage values relative to the full-scale value of the range.

The tolerance in resistance measure­ment is expressed with reference to the scale length of the range.

Frequency range of measurable sig­nals in the measurement of AC vol­tage and current.

Internal resistance between measur­ing terminals. For instance, it is ex­pressed as "MQ" with the DMM and as "KO/V" with the AMT.

It gives a guide for the thickness of a clampable wire.

■ Clamp conductor size

Size of a maximum conductor shape.

It refers to insulating withstand vol­tage of the measuring instrument it­self.

The measuring range of a function is sub-divided and expressed as 2V/20V/200V, etc.

The range is automatically increased or decreased in steps such as 2V/20V/200V and moves to the opti­mum range for measuring voltage.

When a test lead is set at an insulat­ing resistance measuring point on a measuring object, the ACV measuring status starts to check whether voltage is being supplied.

Maximum number of display digits of the digital display. 1999 is expressed as 2000. Three and a half digits and four and a half digits are also used.

Function for measuring voltage, cur­rent, resistance, electrostatic capacity and frequency.

Displayable minimum value of the last digit. For instance, the resolution of the 1.999V range is 0.001V.

True RMS (True root-n^^jl mean-square value) HHi True RMS value. AC cur­rent and voltage of a non-sine wave can be measured by true RMS val­ues.

BBB Frequency ]1 Ya\ Expressed in the unit of Hz BBB (hertz). Commercial fre­quency of 50Hz/60Hz can be meas­ured.

I Data hold

I' Avalué indicated on the display is fixed. It is fixed even after the test lead is removed, and can be used as a record for ref­erence purposes.

The range is fixed in the I measurement of varying voltage and current which is difficult to read in the auto range.

I A certain measured value is assumed as 0 and measured val­ues after that are expressed by posi­tive or negative values relative the value fixed as 0.

BJBJ| Duty cycle

^Tr^l The duty cycle of repeat-

BBB ing waveform is indicated

on a percentage basis (%) . It can

be used for the analysis of control

signals.

a:

he meter element is furn­shed with a taut band and

300V

600V 1000V

The output impedance of an impulse generator i:

^r^B Capacitor

Capacitor capacity (elect-BjhB rostatic capacity) is meas­ured and expressed in the unit of F (farad), ijF, etc.

impact-resistant design enough to withstand a shock of drop.

Resistance is measured by BBB applying voltage of approxi­mately 0.4V or less on a measuring object. It is characterized by the fact that the semiconductor does not conduct at approximately 0.4V or less even in forward direction.

■ Leakage current M^^uJ A clamp meter that can BBB make the measurement of leakage current have a range to al­low measurements in milliamp.

Allows indicator reading in a dark place.

PBH Output terminal |I1H 1 Cancels the DC current HI portion of voltage mixed with DC and AC to measure the AC portion alone. It is used for the measurement of audio signals.

Auto discharge 1| When the measurement of insulating resistance is complete, voltage charged in the measuring object is discharged.

fRS Scale lighting P£5j This is a function for light-BAB ing the scale plate. It is the same function as the backlight func­tion of digital display of the LCD.

BRS232C connection The signal output terminal is provided to send data to a PC. RS232C is the name of the signal standard.

I USB connection

Data can be outputted by I connection to the USB port of a PC.

I Fuse for power sup­ply

I Current-limiting fuse to break the conduction up to 100kA

categories III and IV.

^ ^ CE marking is a safety mark which can be attached only W ^ on a product meeting the safety requirements of the Di-

rective of Council of the European Union (EC Directive). A product attached with the CE mark is designed so as to meet the requirements of the "Low Voltage Directive" and "EMC Directive" of the EC Directive. Low Voltage Directive: This Directive covers prod­ucts of power supply voltage of 50V-1000V (AC) and 75V-1500V(D-C), and it defines electric safety requirements against shocks, burns, etc. The applicable standard is EN61010 corresponding to IEC1010 give on the left. EMC Directive: This Directive stipulates conditions so as not to give out strong electromagnetic waves from equipment to the outer environment and to protect equipment from the effect of electromagnetic waves from the outside.

he LED lights up when measuring object is electrically conducting.

I Continuity buzzer

The buzzer sounds when I the measuring object is electrically conducting.

The peak value like in-rush current

is indicated. The minimum pulse

width capturable differs according to

models.

The minimum value and I maximum value of meas­ured values are recorded. The recor­ded values can be seen later on the display.

The maximum value is I held and displayed in the measurement of voltage, current and ADP.

I Zoom bar graph

The scale is changed so I as to allow reading minute changes on the bar graph.

Battery voltage is meas­ured and assessed by run-a given current.

œhFE Provided with graduations for measuring the DC cur­rent amplification factor (hFE) of a transistor.

4-20mA%

4-20mA for sending instru-I mentation signals. Expres­ses the current loop of 4mA as 0% and 20mA as 100%

For safe measurement

Never use a measuring instrument for a measurement category higher than speci­fied. A tester not conforming to the interna­tional safety standard is for use with weak current. Never use these testers on a high power circuit of 250V or more (excluding PW-100Fb,VS-100). Referring to measure­ment categories defined in the IEC stan­dard, use a measuring instrument of equiva­lent or higher category. For instance, when a measuring instrument is used on a motor of facility of 200V main power supply, which corresponds to Categorylll, use a measur­ing instrumentofCAT.III or higher. Current measurement Use special caution not to input voltage to the current measuring terminal in measure­ment. In current measurement, a meter is connected in series with the measuring cir­cuit. For this reason, impedance inside the meter is low, thereby possibly causing a short-circuit fault. To prevent such a short-circuit fault and assure safe operation, fuses are installed for protection. Check the pro­tection capability of the fuses. RD700 uses a quick-breaking ceramic fuse of rated vol­tage 250V and breaking current 1.5kA for the milliamp measuring circuit, which cau­ses the fuse to blow out to prevent short-cir­cuit when the main power supply is 250V or

•Use all clamp meters for measurement of

low voltage circuit of 600V or less, •in choosing an appropriate model, special attention should be paid to the current measurement range and diameter of a conductor to be clamped. Insulation resistance tester •The insulation resistance tester cannot be used on an measuring object in live-wire status.

•if the measuring voltage is specified, choose a model of the specified voltage. It is a general practice to choose the measuring voltage equivalent to or a little higher than voltage usually applied to the measuring object. •Since the insulating-resistance tester measures resistance values by applying DC high voltage on a measuring object, the measurement may damage the meas uring object if voltage is directly applied on he electronic circuit including the IC and LSI. •The insulating-resistance tester generates DC high voltage during measurement. If an electric shock occurs, a falling accident from a high altitude may follow. Use special caution in operation at a high altitude, ^f your measuring instrument is provided with a voltage measuring function, use it at no higher than the maximum measuring voltage.

The temperature sensor cannot be used for measurement in direct contact with a live part.

Use caution in handling a sharp-edged

probe to avoid an injury.

The grip is heated in high temperature

measurement. Use an appropriate jig to

secure the probe in high temperature

measurement.

Tachometer - Speed Meter In measurement on a rotating motor (m-easurement of speed for elevator in opera­tion) , risks are involved due to the strong force of the measuring object. Use special caution in measurement to assure safety. Never touch the rotating part during meas­urement.

•infrared semiconductor laser light is invisi ble to the naked eye. It may occasionally emit high power of 30mW or more, which may threaten vision if eyes are exposed to the light. Use special caution to avoid gaz­ing at the light directly or exposing eyes to reflected light.

I dBm

| Scaling of voltage values is performed according to the reference impedance into dBm. Convenient for use with audio equip­ment.

I Temperature measurement

Temperature can be measured using the optional probe.

I Correction of resis­tance of test lead

This is a function to cancel the resistance portion of the internal circuit of the main body andtest lead in the resistance measurement.

^^¡1 Auto polarity

Puts the indicator at the cen-I ter in the automatic standby status by the setting of the selector switch so as to allow measurement by positive and negative values.

The positive and negative I polarity of the measuring terminal can be changed by this switch.

Temperature TÉ measurement 3 with PC Link

Temperature can be measured using the optional probe and PC Link software. (T-300PC is necessary.)

ifWS Insulating resis-LyJ tance

BiI^B Insulating resistance can be measured (e.g. 500V/1000MO)

ower is automatically urned off when a certain

time has elapsed after power-up. Some models have a function to cancel this function.

Mark for clamp meters with DCV function.

IAuto power save The display disappears to bring the device into the pow­er-save state when a certain time has passed after power-up. Some models have a function to cancel this function.

ancels the contact resis-ance and internal resis­

tance of the test lead to allow the measurement of the resistance val­ue of a measuring object alone.

less and short circuit current is 1.5kA or less.

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