FAQ

You may not be able to use some PC cards that typically are available for purchase in computer stores and other shops. Please use a genuine HIOKI product for which HIOKI has verified proper operation.

Vertical-axis full scale on the Memory HiCorder MR8847 is 20 div. Since the resolution is 1/100 of the range, the number of data points in the range that can be shown on the display is 2,000. However, the instrument actually records 4,000 data points, including those that fall outside the display range. By doing so, it makes it possible to check waveforms outside the screen range by moving the zero-position up or down after recording is complete. Consequently, the user manual and catalog indicate that the instrument uses 12-bit A/D conversion. Please note that the measurement resolution relative to the range varies with the input module and Memory HiCorder or other equipment being used.

The maximum rated voltage to earth is the upper limit voltage that can be applied between input channel and the instrument’s enclosure or between input channels without damaging the instrument. By contrast, the maximum rated input voltage is the upper limit voltage that can be applied between input terminals without damaging the instrument.

You may not be able to use some PC cards that typically are available for purchase in computer stores and other shops. Please use a genuine HIOKI product for which HIOKI has verified proper operation.

The LR8431 can use USB flash drives and is set to do so by default when it ships from the factory. To use the Logger Utility, change the USB mode from “USB flash drive” to “USB communications” on the System screen.

Attach a 250 Ω resistor to the Memory HiLogger’s terminal block along with the signal wires so that the 4 to 20 mA current is converted to, and input as, a 1 to 5 V voltage. The Memory HiLogger’s 1 to 5 V measurement range is convenient in this setup. You can also use the instrument’s scaling function to convert displayed values to desired values.

The Clamp On Power Logger PW3360 series testers save data on the Z4001, a 2 GB SD card. For example, if “Average only” is selected as the save parameter while using the 3P2W2M setting, the following save times are achieved (time shown on the PW3360):

Save interval time: 1 sec. → 42.4 days
2 sec. → 84.9 days
5 sec. → 212 days
10 sec. or more → 1 year

If “All” is selected as the save parameter while using the 3P3W2M setting, the following save times are achieved:

Save interval time: 1 sec. → 16.1 days
2 sec. → 32.3 days
5 sec. → 80.7 days
10 sec. → 161 days
15 sec. → 242 days
30 sec. → 1 year

The maximum file size for measurement data is approximately 200 MB. When this amount is exceeded, a separate file will be created, and data will be saved in the new file.

Reference: The PW3360 series testers’ maximum recording time is 1 year.

Typically, you should use a true RMS instrument to measure the current and voltage on the primary side of an inverter because such instruments can accurately measure distorted waveforms. The same type of instrument should be used to measure the current on the secondary side of an inverter. By contrast, you should use a average rectified-type instrument to measure the voltage on the secondary side of an inverter. Use of the average rectification method makes it possible to obtain values that are close to the fundamental component. Therefore, it is recommended to use a true RMS tester to measure the current and voltage on the primary side of an inverter as well as the current on the secondary side, and a average rectified-type tester to measure voltage on the secondary side.

You can download the sample application and view the Communications Command User Manual here.

The instrument saves data in either CSV or BMP format.

Inductors with cores exhibit current dependency. Air-core inductors do not exhibit current dependency. An LCR meter’s V and CV (constant-voltage) modes can be used to measure samples that exhibit voltage dependency (ceramic capacitors, etc.). Select CV mode when you do not wish to change the voltage applied to both ends of the sample. To the extent that the voltage value is monitored and controlled with feedback, CV mode results in longer measurement times than V mode.

When measuring the resistance of an inductor or transformer after conducting an insulation withstanding test, you could damage the resistance meter if the output voltage from the insulation withstanding tester is inadvertently applied to it. Exercise caution concerning the following when using a custom-designed switching system to perform measurement. Ensure that the switching device (relay, switch, etc.) does not cause the high voltage from the insulation withstanding tester to be applied to the resistance meter. Additionally, allow sufficient time for the measurement target to discharge after the test before performing resistance measurement as it will have become charged.

When a current I is applied to the object under measurement, a resistance R and the voltage V are generated with the relationship R = V / I. The resistance R can be calculated using this relationship. Resistance meters provide three measurement methods: constant current (CC), which applies a constant current to the sample; constant voltage (CV), which applies a constant voltage to both ends of the sample; and a third that applies the voltage across the combination of the instrument’s output impedance and the series-connected sample. HIOKI resistance meters use the CC method. Super-insulation resistance meters use the CV method, and some LCR meters allow the user to select any of the three methods.
Applicable products: 3541, RM3542, RM3543, RM3544, RM3548

Since industrial-use alkaline batteries exhibit only a small change in resistance value when they deteriorate, it is difficult to use the 3554 to diagnose deterioration in service life (by measuring changes in internal resistance).

If the measured values are unstable as described below, try the suggested action under “Causes and solutions.”

Symptoms
1. The measured values are abnormal.
2. The instrument display shows “----.”
3. The instrument display shows “OF.”

Causes and solutions
1. There is a wiring break in the test leads. → Replace the test leads.
*Test leads that have been bent frequently in the past may develop a break in their wiring.
2. The test leads are not connected properly. → Connect the test leads properly.
3. The 3554’s fuse has blown. → Replace the fuse.
4. Zero-adjustment has not been performed properly. → Perform zero-adjustment properly.
5. An appropriate range has not been selected. → Select an appropriate range with the instrument’s range button.
6. The tip of the pin-type lead is damaged. → The tip pin on the 9465-10 and 9772 (9465-90/9772-90) is user-replaceable.

The instrument ships with its double-action function activated for safety reasons. This function ensures that measurement does not start if the START button is not pressed within 0.5 seconds of the STOP button being pressed. If you do not require this function to be enabled, it can be disabled as described on page 81 of the user manual.

For example, IEC 61010 (Appendix F) addresses shortening of testing time. Please consult the specifications you’re using as specific rules vary. If there is a routine test item in the specifications, you should be able to refer to that.

The instrument will not make measurements or judgments until the actual output voltage reaches the set test voltage. Depending on the device being tested, it may take some time for the test voltage to be reached. For example, if there is capacitance, it may take time for the test voltage to be reached due to the time constant, which is determined by the capacitance and resistance values. With high resistance, the time constant for the measurement circuit may cause it to take some time for measured values to be displayed.

“OF” means “overflow,” and it is equivalent to an infinite result on an analog insulation resistance meter. Digital Megaohm HiTesters display “OF” when the measured value is greater than or equal to the resistance display range. As a rule, this indicates extremely good insulation, although you should short the test lead tips on a regular basis to verify that there are no broken connections causing this result.

The instrument may be set to the wrong power supply frequency. This can have a pronounced effect during high-resistance measurement. Precaution concerning high-resistance measurement: Since this type of measurement is susceptible to the effects of external noise, shield the red leads and the measurement target and connect the shielding to the instrument’s COM terminal.

Although internal resistance would ideally be infinite, testers always have a certain internal resistance. DMMs have a high internal resistance that is generally at least 10 MΩ (although it may vary with the measurement range), while analog testers (3030-10, 3008) have a DC voltmeter with an internal resistance of 20 kΩ/V (the 3030-10’s 0.3 V range has an internal resistance of 16.7 kΩ/V). When measuring a circuit’s voltage, the tester’s internal resistance is connected in parallel with the actual measurement circuit. The magnitude of the effect of the internal resistance is determined by the proportion of the resistance of the circuit being measured to the tester’s internal resistance, and it decreases as the tester’s internal resistance increases. Consequently, it is necessary to exercise caution when measuring a high-resistance circuit such as a transistor base circuit with a tester that has a low internal resistance, because the indicated voltage will be lower than the actual voltage.

It is not problematic to use a 24 V power supply. Use constant-current output from -4 to -20 mA. Both the SS7012 and 7016 generate bipolar output that can operate as either sink or source.

You may not be able to use some PC cards that typically are available for purchase in computer stores and other shops. Please use a genuine HIOKI product for which HIOKI has verified proper operation.

Typically, you should use a true RMS instrument to measure the current and voltage on the primary side of an inverter because such instruments can accurately measure distorted waveforms. The same type of instrument should be used to measure the current on the secondary side of an inverter. By contrast, you should use a average rectified-type instrument to measure the voltage on the secondary side of an inverter. Use of the average rectification method makes it possible to obtain values that are close to the fundamental component. Therefore, it is recommended to use a true RMS tester to measure the current and voltage on the primary side of an inverter as well as the current on the secondary side, and a average rectified-type tester to measure voltage on the secondary side.

The 3390 and 3390-10 do not differ in terms of functionality. The 3390-10 provides high-accuracy performance for the following ranges when used in combination with a specially designed high-accuracy pass-through sensor:
Voltage: DC
Current and active power: DC and 45 to 66 Hz frequency range
Power factor effect (active power with a low power factor): 45 to 66 Hz frequency range
In other frequency ranges, the 3390-10 delivers the same level of accuracy as the 3390 used with the CT6862, CT6863, or 9709.
High accuracy is guaranteed when used in combination with the CT6862-10, CT6863-10, and 9709-10. High accuracy is only guaranteed when these sensors are used in combination with the 3390-10.

When connecting the instrument, the voltage input terminals can be connected to the load, or the current terminals can be connected to the load. Which connection should be used varies with the magnitude of the voltage and current being measured.

Connecting the voltage terminals to the load
Power measurements will include loss from the voltage input terminals’ input resistance. Loss due to the instrument can be minimized when the measured voltage is low and the measured current is small.

Connecting the current terminals to the load
Power measurements will include loss from the current input terminals’ input resistance. Loss due to the instrument can be minimized when the measured voltage is high and the measured current is small.

When using clamp-on sensor input, the sensor’s loss can be ignored for the most part.

You may not be able to use some PC cards that typically are available for purchase in computer stores and other shops. Please use a genuine HIOKI product for which HIOKI has verified proper operation.

The Clamp On Power Logger PW3360 series testers save data on the Z4001, a 2 GB SD card. For example, if “Average only” is selected as the save parameter while using the 3P2W2M setting, the following save times are achieved (time shown on the PW3360):

Save interval time: 1 sec. → 42.4 days
2 sec. → 84.9 days
5 sec. → 212 days
10 sec. or more → 1 year

If “All” is selected as the save parameter while using the 3P3W2M setting, the following save times are achieved:

Save interval time: 1 sec. → 16.1 days
2 sec. → 32.3 days
5 sec. → 80.7 days
10 sec. → 161 days
15 sec. → 242 days
30 sec. → 1 year

The maximum file size for measurement data is approximately 200 MB. When this amount is exceeded, a separate file will be created, and data will be saved in the new file.

Reference: The PW3360 series testers’ maximum recording time is 1 year.

Typically, you should use a true RMS instrument to measure the current and voltage on the primary side of an inverter because such instruments can accurately measure distorted waveforms. The same type of instrument should be used to measure the current on the secondary side of an inverter. By contrast, you should use a average rectified-type instrument to measure the voltage on the secondary side of an inverter. Use of the average rectification method makes it possible to obtain values that are close to the fundamental component. Therefore, it is recommended to use a true RMS tester to measure the current and voltage on the primary side of an inverter as well as the current on the secondary side, and a average rectified-type tester to measure voltage on the secondary side.

When connecting the instrument, the voltage input terminals can be connected to the load, or the current terminals can be connected to the load. Which connection should be used varies with the magnitude of the voltage and current being measured.

Connecting the voltage terminals to the load
Power measurements will include loss from the voltage input terminals’ input resistance. Loss due to the instrument can be minimized when the measured voltage is low and the measured current is small.

Connecting the current terminals to the load
Power measurements will include loss from the current input terminals’ input resistance. Loss due to the instrument can be minimized when the measured voltage is high and the measured current is small.

When using clamp-on sensor input, the sensor’s loss can be ignored for the most part.

The Power Quality Analyzer PW3198 can use a single measurement interval of up to 35 days in length. However, you can configure repeat recording if you wish to record longer periods of time. You can repeatedly record data every day or week and save it on the SD card for up to 55 weeks (when using a 2 GB SD card).

As a rule, the card should not be removed during measurement. The data will be corrupted if the card is inserted or removed while the instrument is saving data. If you must capture measurement data during measurement, the card can be removed during interval measurement while the instrument is not saving data. Please avoid removing the card if using a short interval time.

When you look at measurement data from the Clamp On Power HiTester 3169 in 3P3W2M mode, you’ll find P1 and P2 values. Regardless of whether the instrument has been connected properly, one of the two values may be negative. For example, the P1 measured value may be negative when measuring the power of a motor operating under a light load. The 3169’s 3P3W2M mode uses two-power measurement. Since the 3-phase power is calculated by adding P1 and P2 (as per Blondel’s theorem), it is not a problem for either P1 or P2 to be negative as long as the instrument has been connected properly.

The connection check function may indicate an error even though the instrument is connected properly, or it may yield an OK result even though the instrument is not connected properly. Check for problems with the vector display or measured values. Particularly when the power factor is 0.5 or less, the phase difference (I-U) may trigger an error even if the instrument is connected properly. If you check the connection and find no problem, measurement can be performed without issue despite the indicated error.

When CSV-format data from the 3169 is opened in Excel, it is displayed using exponents. “1.05E+02” means 1.05×102.

The voltage indicated with the CAT II to CAT IV measurement category is the voltage to ground. For example, with a 3-phase/3-wire or 3-phase/4-wire 400 V circuit, the line voltage is 415 V, but the voltage to ground is 240 V. Consequently, a CAT III (300 V) measuring instrument can be used to safely measure a 400 V line in a location that falls under CAT III. All current testers, DMMs, and clamp-on ammeters that bear the CE mark are designed for use in CAT III measurement of 300 V or higher.

*CAT III: A circuit from the primary side of a device (fixed equipment) drawing electricity directly from a distribution panel or from a distribution panel to an outlet

The LAN Cable HiTester 3665 uses time domain reflectometry (TDR) to measure LAN cable length. The instrument sends a pulse signal from the end of the cord and measures the time difference when the signal returns, which it then uses to calculate the cable length.

In general, there is no limit on the measuring distance for infrared thermometers, but the field of view becomes problematic. Infrared thermometers work by detecting infrared energy emitted from the object being measured. The distance at which measurement is performed should be determined based on the infrared thermometer’s measuring field of view. While this differs depending on the model, the further away the instrument, the larger the field of view. Keep in mind that the temperature reading represents the average temperature in that field of view.

Typically, you should use a true RMS instrument to measure the current and voltage on the primary side of an inverter because such instruments can accurately measure distorted waveforms. The same type of instrument should be used to measure the current on the secondary side of an inverter. By contrast, you should use a average rectified-type instrument to measure the voltage on the secondary side of an inverter. Use of the average rectification method makes it possible to obtain values that are close to the fundamental component. Therefore, it is recommended to use a true RMS tester to measure the current and voltage on the primary side of an inverter as well as the current on the secondary side, and a average rectified-type tester to measure voltage on the secondary side.

Although internal resistance would ideally be infinite, testers always have a certain internal resistance. DMMs have a high internal resistance that is generally at least 10 MΩ (although it may vary with the measurement range), while analog testers (3030-10, 3008) have a DC voltmeter with an internal resistance of 20 kΩ/V (the 3030-10’s 0.3 V range has an internal resistance of 16.7 kΩ/V). When measuring a circuit’s voltage, the tester’s internal resistance is connected in parallel with the actual measurement circuit. The magnitude of the effect of the internal resistance is determined by the proportion of the resistance of the circuit being measured to the tester’s internal resistance, and it decreases as the tester’s internal resistance increases. Consequently, it is necessary to exercise caution when measuring a high-resistance circuit such as a transistor base circuit with a tester that has a low internal resistance, because the indicated voltage will be lower than the actual voltage.

Since the resistance function measures the target resistance by passing a current through it, the input resistance between the measurement terminals is low. Therefore, the tester is protected by damage in the event of an overvoltage input by an overcurrent protection device, which makes it difficult for current to flow.

Broadly speaking, there are two measurement methods.

Constant-voltage method: The current is given by the resistance value being measured and the internal circuit’s reference resistance value and protective resistance, and it varies with the measurement voltage that is applied. I = Measurement voltage / (Reference resistance + protective resistance + resistance being measured)

Constant-current method: A constant current flows to the resistance being measured, and the resistance value is calculated from the resulting voltage drop. Measurement currents for individual ranges can be checked in the product’s user manual.

The voltage function receives a voltage signal with an input resistance of 10 MΩ. The high input resistance itself serves as input protection.

Tester damage is prevented by means of a fuse. During current measurement, current flows to the detection resistor (shunt resistor), and the current is calculated based on the resulting voltage drop. Since the input resistance between the current measurement terminals is low, application of an overvoltage would cause a large current to flow momentarily. Consequently, the protective fuse is selected based on a consideration of that fact.

The IEC 61010-031 international safety standard for probes was revised, and the new standard went into effect in March 2011. There were two major changes made in response to safety-related requests. The pins on the tips of test probes used for CAT III and CAT IV measurements are now required to limit exposed metal to 4 mm or less (compared to 19 mm previously) to prevent short-circuits and to use two layers of differently colored insulation to allow cable wear to be detectable visually (compared to a single layer previously). HIOKI will modify its testers, probes, and other measurement products over time to comply with these revisions. Safety categories are also defined based on the measuring instrument itself. For example, even if the probe being used is a CAT III 1,000 V model, the CAT III 600 V safety standard will apply if the measuring instrument being used is a CAT III 600 V model.

When using an analog tester, after switching from the voltmeter to the resistance meter, the voltmeter’s positive lead is the resistance meter’s negative lead, and the voltmeter’s negative lead is the resistance meter’s positive lead. Please be sure that you understand this fact before using the instrument.

The voltage indicated with the CAT II to CAT IV measurement category is the voltage to ground. For example, with a 3-phase/3-wire or 3-phase/4-wire 400 V circuit, the line voltage is 415 V, but the voltage to ground is 240 V. Consequently, a CAT III (300 V) measuring instrument can be used to safely measure a 400 V line in a location that falls under CAT III. All current testers, DMMs, and clamp-on ammeters that bear the CE mark are designed for use in CAT III measurement of 300 V or higher.

*CAT III: A circuit from the primary side of a device (fixed equipment) drawing electricity directly from a distribution panel or from a distribution panel to an outlet

The growing popularity of switching power supplies and inverter-equipped devices has made it more likely that harmonic components may be superposed on leak current waveforms. The filter function provided by the 3283 and 3293-50 corresponds to the earth leakage breaker (ELB) response frequency. By turning the filter function on, you can achieve the same frequency bandwidth (180 Hz) as an ELB, allowing measurement of leak current with a commercial power frequency component.

If there is no leak current, the magnetic flux generated around the conductive wire from the power supply and the magnetic flux of the current in the returning wire cancel each other out, causing the clamp leak current meter to indicate a reading of 0. However, if there is a leak on the load side of the clamped conductor, there will be a difference between the magnetic flux of the outgoing current and the returning current, and the magnetic flux corresponding to this difference will be the current that is leaking on the load side. Similar leak current measurement can be performed for a 3-phase circuit by clamping all three wires at once.

The discrepancy with the inverter’s display value could be due to the following causes:
• The inverter may be displaying the primary-side current value.
• The value may be affected by inverter noise and harmonics.
• The difference may derive from the difference between RMS (true RMS) and MEAN (average rectified) measurement. (The 3285 uses RMS.)

Although the 3281 and 3282 offer peak hold capability through the combination of peak measurement and recording measurement, these instruments are not able to capture crest values 100% of the time. The 3281 updates the data every 250 ms. Measurement takes 128 ms, but calculation and display processing take up the remaining time, raising the possibility that a peak might be missed.

Use of inverters that utilize semiconductor control elements has surged recently in manufacturing plants and other facilities, leading to an increase of cases in which leak currents flowing to grounding lines include not only fundamental components as in the past, but also numerous harmonic components. When measuring grounding lines that remain connected, for example during maintenance inspections, harmonic current leaking from equipment may prevent indicated values from stabilizing. Two frequencies are provided so that it is possible to limit interference with harmonic currents by switching the frequency being measured in such situations and thereby allow stable measurement (575 Hz and 600 Hz). If the indicated value fails to stabilize, try switching the frequency.

The clamp part of the Clamp On Earth Tester FT6380/FT6381 has a two-layer core that includes a voltage injector and a sensor to measure current. The clamp is applied to the measurement target’s grounding resistance Rx, and the voltage V is injected from the voltage injector. Using the constant voltage and measured current, the overall resistance of a loop with multiple groundings can be calculated with the following formula: Rx + 1/(1/R1 + 1/R2 + 1/R3 + 1/R4…) = V / I. *If the second term on the left side of the formula is sufficiently less than the first term (grounding electrodes are connected in parallel; when there are many grounding electrodes, the second term decreases the more grounding electrodes there are), Rx can be expressed as follows: Rx = V/I. The FT6380 and FT6381 can measure multiple groundings in which a single wire is grounded multiple times. Multiple groundings include structural groundings and groundings used at chemical plants and for communications. These instruments cannot be used to measure single or independent groundings such as those for which residential grounding electrodes are used.

The Phase Detector 3129 uses a static induction voltage sensor. When clipped an insulated wire, this sensor can measure the voltage to earth by means of capacitive coupling, allowing the instrument to detect the voltage phase (R, S, or T), display a red lamp, and indicate the phase order. Unlike conventional phase detectors that had to be clipped directly to a live metal conductor, this product safely prevents contact and short-circuit accidents.

In addition to the standard 100 V AC model, HIOKI can manufacture units with a supply voltage of 200 V AC if specified at the time of order. Supply voltages of 110 V AC, 120 V AC, 220 V AC, 230 V AC, 240 V AC, 12 V DC, and 24 V DC are also available by special order.