Hioki CHT3548 User Manual Download Page 43 | Manualshive

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Hioki CHT3548 User Manual Download Page 43

Hope Electronics Technology

Manual

Edition

V1.0

43

4.4 Compensating for Thermal EMF Offset (Offset Voltage

Compensation Function: OVC Function)

This function automatically compensates for an offset voltage caused by

thermal EMF or an internal offset voltage.

(OVC: Offset Voltage Compensation)
See: “Appx. Effect of Thermoelectromotive Force (Thermal EMF)”.
The function uses the resistance value measured when a measurement

current flows, RP and that measured when no measurement current flows, RZ,
to display the actual resistance value RP-RZ.

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Summary of Contents for CHT3548

Page 1: ...CHT3548 User s Manual RESISTANCE METER 2015 4 15 Hope Electronics Technology Manual Edition V1 0...

Page 2: ...ction 40 4 3 Compensating for Thermal Effects Temperature Correction TC 41 4 4 Compensating for Thermal EMF Offset Offset Voltage Compensation Function OVC Function 43 4 5 Setting the Delay Time for M...

Page 3: ...ngs 71 8 1 confirmation screen displays the date and time 71 8 2 calibration clock 71 8 3 initialized reset 73 Chapter 9 Appendix 74 Appx 1 block diagram 74 Appx 2 Four Terminal Voltage Drop Method 75...

Page 4: ...o ensure that no damage occurred during shipping In particular check the accessories panel switches and connectors If damage is evident or if it fails to operate according to the specifications contac...

Page 5: ...ould result in injury or death as wellas damage to the instrument Be certain that you understand the instructions and precautions in the manual before use Notation This manual contains information and...

Page 6: ...the instrument or relative suggestion of a correct operation Accuracy We define measurement tolerances in terms of f s full scale rdg reading and dgt digit values with the following meanings f s Maxim...

Page 7: ...ent the first time verify that it operates normally to ensure that no damage occurred during storage or shipping If you find any damage contact your authorized Hopetech distributor or reseller Before...

Page 8: ...ration or shock during transport or handling Especially be careful not to drop or fall the instrument which will cause shock To avoid any damage to the instrument do not input voltage or current to an...

Page 9: ...tandard auto memory and auto hold and optional L2105 LED Comparator Attachment Highly reliable specifications implemented in a compact light weight body l 35 000 dgt high resolution l 0 1 resolution a...

Page 10: ...Hope Electronics Technology Manual Edition V1 0 10 1 2 Component Names and Operation Overview Front Panel Rear Panel Rear panel...

Page 11: ...function oFF ON AVG key Averaging function oFF 2 5 10 20 OVC key press and hold Offset voltage compensation OVC function oFF oN MODE key Switches memory hold mode oFF A HOLD auto hold A HOLD A MEMORY...

Page 12: ...MORY CLEAR key press and hold Clears memory LASt Latest data from the selected block bLoC Selected block ALL All data INTERVAL key press and hold Starts stops interval measurement when in interval mod...

Page 13: ...Hope Electronics Technology Manual Edition V1 0 13 Clearing all measurement data saved Resetting the current measurement conditions Resetting the system...

Page 14: ...ire display is lit Displays measurement conditions settings measured values memory numbers MEMORY No panel numbers comparator settings judgment results etc For information on the error display see Err...

Page 15: ...Hope Electronics Technology Manual Edition V1 0 15 Temperature conversion T measurement screen Interval measurement screen Non measured value display Out of range Current fault...

Page 16: ...is enabled Blinking Zero adjustment is in progress A HOLD The auto hold function is enabled A MEMO The auto memory function is enabled The beeper function is enabled APS The auto power save function i...

Page 17: ...doing the settings for each function COMP Comparator function is enabled PASS The notation appears when the comparator judgement result is confirmed as qualified FAIL The notation appears when the com...

Page 18: ...ns appropriately according to the measurement target Before starting measurement use the examples recommended in the following table to configure the instrument l When the measurement target significa...

Page 19: ...Hope Electronics Technology Manual Edition V1 0 19 1 5 Dimension...

Page 20: ...ng the strap to the instrument allows you to use it with the strap around your neck Follow the procedure below to attach the strap Note Use the four attachment points on the instrument to attach the s...

Page 21: ...reattach the cover Poor performance or damage from battery leakage could result Observe the cautions listed below Do not use both new and old batteries or different types of batteries together Be car...

Page 22: ...Hope Electronics Technology Manual Edition V1 0 22 Lithium battery replacement...

Page 23: ...t use any test lead other than the ones specified by our company l The ends of leads are sharp Be careful to avoid injury Connect the test leads to the instrument Connect the four terminals DRIVE and...

Page 24: ...turn the power off Hold the key down until the entire display turns off Entire display off IMPORTANT When the instrument is turned on again it starts up with the previous state used immediately befor...

Page 25: ...The setting of the APS function is not saved When the instrument is turned on again the APS function is enabled again Then when a specific time elapses after the start of blinking the instrument auto...

Page 26: ...Hope Electronics Technology Manual Edition V1 0 26...

Page 27: ...metal exposed If the coating of a test lead is broken the measured value may become unstable or have an error Replace the damaged test lead Power on checking Inspection item Action Is the remaining b...

Page 28: ...mately 2 W may be applied If there are any of the following concerns depending on the level of the measurement current select a range using a lower measurement current l The measurement target may mel...

Page 29: ...the comparator function is turned ON the range is fixed and cannot be changed To change the range turn the comparator function OFF or change the range in the comparator setting l Depending on the mea...

Page 30: ...Hope Electronics Technology Manual Edition V1 0 30 3 2 Connecting the Test Leads to the Measurement Target Example 9363 A Test clip Example 9363 B Test Probe...

Page 31: ...of a Conductor Length Conversion Function Switching the display Press and hold the VIEW key to switch the type of information displayed on the upper right of the screen Temperature no indicator memory...

Page 32: ...d if oF is displayed the comparator judgment is Lo In the same manner oF is displayed when the temperature exceeds the measurement range during temperature measurement Current fault or not measured ye...

Page 33: ...vervoltage input If an overvoltage is accidentally applied and a fuse is blown replace the fuse Temperature Sensor not connected Temperature cannot be measured as the Temperature Sensor is not connect...

Page 34: ...ion function exceeds 999 99 km 2 Current fault detection function Current fault examples l The DRIVE or DRIVE probe is open l The measurement target has a broken wire open circuit work l The DRIVE or...

Page 35: ...nual Edition V1 0 35 Save a measured value The storage function helps to verify a measured value later It saves the displayed measured value For more details about the save function see Saving Data at...

Page 36: ...PORTANT l When the ambient temperature changes or the test leads are replaced after zero adjustment perform zero adjustment again l Perform zero adjustment for each range used In the manual range mode...

Page 37: ...justment 1 Short the test leads Example 9363 A Test CliP p Correct Incorrect Example 9363 B Text Probe 2 Confirm that the measured value is within 3 f s If no measured value is displayed make sure tha...

Page 38: ...nt If it is difficult to press the key as the Zero Adjustment Board is used press the 0 ADJ key before shorting the measurement lead Zero adjustment is automatically performed after the measured value...

Page 39: ...each range or the instrument is in a measurement error state Perform zero adjustment with the correct wire connection again If the resistance is too high e g due to a self made cable zero adjustment c...

Page 40: ...hnology Manual Edition V1 0 40 4 2 Stabilizing Measured Values Averaging Function This function averages the measurement values in order to display a single value It helps to stabilize fluctuations in...

Page 41: ...on the reference temperature to display the converted value For the principles of temperature correction see Appx Temperature Correction Function TC To perform temperature correction connect the Tempe...

Page 42: ...ctronics Technology Manual Edition V1 0 42 IMPORTANT If the t Err is displayed the Temperature Sensor may not be connected or Of is displayed for the temperature Check the connection of the Temperatur...

Page 43: ...ally compensates for an offset voltage caused by thermal EMF or an internal offset voltage OVC Offset Voltage Compensation See Appx Effect of Thermoelectromotive Force Thermal EMF The function uses th...

Page 44: ...elay value factory default Unit ms Measurement current Range Delay time Lo 3m 30m 200 300m 3 50 30 300 30 Hi 300m 200 IMPORTANT l When the offset voltage compensation function is ON the OVC indicator...

Page 45: ...me to approximately ten times the following calculation so that the reactance component inductance or capacitance does not affect the measurement L Measurement target inductance R Measurement target r...

Page 46: ...ns It is also useful when performing measurement in an environment with external noise When measurement is performed with the 300 mA measurement current the 300 mA indicator lights up 1 When measuring...

Page 47: ...ement current This is due to an oxide film that is generated around the contact while it is not used l Even when it is judged that no abnormality is found using a small current the connection sections...

Page 48: ...mparator Attachment option There are two different judgment methods available ABS mode and REF mode Before using the comparator function If no measured value appears the comparator judgment is display...

Page 49: ...e Set the upper and lower limit values for judgment as absolute values Example Upper limit value 100 00 m Lower limit value 80 00 m Upper limit value 100 00 m REF relative value judgment mode Set the...

Page 50: ...Hope Electronics Technology Manual Edition V1 0 50 Judging based on upper and lower limit values ABS mode...

Page 51: ...ed on a reference value and allowable range REF mode In REF mode a measured value is displayed as a relative value The upper and lower limit values cannot be set separately IMPORTANT Any setting chang...

Page 52: ...anual Edition V1 0 52 Verifying a judgment with a sound judgment sound function This function sounds the buzzer based on a comparator judgment result IMPORTANT The settings cannot be confirmed when th...

Page 53: ...Hope Electronics Technology Manual Edition V1 0 53...

Page 54: ...1 After the motor and coil are stabilized at room temperature measure the resistance R1 and instrument ambient temperature t1 and then input these values to the instrument 2 Disconnect the test lead...

Page 55: ...Hope Electronics Technology Manual Edition V1 0 55 Measurement screen 5 3 measuring conductor length length conversion function...

Page 56: ...he TC T LENGTH key to display the ON OFF setting screen for the length conversion function Example When the measured resistance is 8 and per meter resistance is 100m m Measuring the Length of a Conduc...

Page 57: ...ANT The display format decimal point position and unit automatically changes depending on the range and setting For details see the product specifications For some ranges oF is always displayed becaus...

Page 58: ...splay the panel load screen Press and hold the PANEL SAVE CLEAR key to display the setting screen for the panel save clear function Conditions that can be saved by panel save Resistance measurement ra...

Page 59: ...3 Select a panel number 4 Press the ENTER key to delete the panel move to the measurement screen IMPORTANT l If the already saved panel number is selected and the ENTER key is pressed the existing co...

Page 60: ...Hope Electronics Technology Manual Edition V1 0 60 IMPORTANT Once deleted the contents of the panel cannot be restored...

Page 61: ...nd time measurement value temperature resistance measurement range averaging temperature correction TC temperature conversion T and interval Memory layout Memory block 10 blocks Maximum number of entr...

Page 62: ...dition V1 0 62 1 Press the M BLOCK key to go to the memory block selection screen 2 Rolling the or key to change the memory block 3 Press the Enter key to move the measurement screen or press the Esc...

Page 63: ...s any timing to save manual storage Press the ENTER MEMO key to save the displayed measured value The memory number is incremented by one each time data is saved and cannot be specified If data is acc...

Page 64: ...and saved Press the MODE key to switch saving mode oFF Auto hold A HOLD Auto memory A HOLD A MEMORY Interval INTERVAL oFF Press the ENTER key to confirm the saving mode press the ESC key to cancel the...

Page 65: ...rm a temperature rise test for estimation of power off temperature Press the MODE key to switch the saving mode oFF Auto hold A HOLD Auto memory A HOLD A MEMORY Interval INTERVAL oFF Press the key to...

Page 66: ...IMPORTANT l When an interval measurement starts data is automatically saved in an available free block The memory block used cannot be changed When the interval measurement stops the used memory block...

Page 67: ...Manual Edition V1 0 67 7 4 Display saved measurement data stored display Press the READ key to display the saved measurement data Press the key to change the saved read number Press ENTER or ESC key t...

Page 68: ...clear saved measurement data l Clearing only the last data latest data saved in a block l Clearing an entire block l Clearing all Press and hold the READ MEMO CLEAR key to display the clearing measur...

Page 69: ...the plugs to the instrument and PC Removing the USB cable To remove the USB cable connected to the instrument while the PC is running use the Safely Remove Hardware icon on the PC Install desktop soft...

Page 70: ...Hope Electronics Technology Manual Edition V1 0 70 After the connecting successfully click data to read measurement Click the data export the data can be exported to a CSV file...

Page 71: ...mation screen displays the date and time Press and hold the DATE key to verify the date and time Press the Esc or Enter key to return the measurement screen 8 2 calibration clock Set the date and time...

Page 72: ...Manual Edition V1 0 72 Press key to switch the digits items press the key to change the values Press the Enter key to confirm and switch the time and date screen Press the Esc key to cancel and switc...

Page 73: ...ement data This type of initialization is possible even if the power is on Reset to reset the current measurement conditions Resets data and settings other than the panel data saved measurement data a...

Page 74: ...ce easily l During measurement it is monitored whether normal constant current flow is present in the measurement target C l In addition to resistance temperature is measured with a thermistor tempera...

Page 75: ...method is essential for measuring very small resistance values With two terminal measurements Fig 1 the resistance of the test leads is included in the measured resistance resulting in measurement er...

Page 76: ...impedance of the voltmeter allows only negligible current flow through r3 and r4 So the voltage drop across r3 and r4 is practically nil and voltage E across the measurement terminals and voltage E0...

Page 77: ...of an DC power supply and DC voltmeter While its simple circuitry makes it easier to increase accuracy it is prone to measurement errors due to electromotive force that may be present in the measurem...

Page 78: ...the measurement target having resistance temperature coefficient at t0 C of t 0 at t C and t 0 C Example If a copper test object with a resistance temperature coefficient at 20 C of 3930 ppm measures...

Page 79: ...the temperature coefficient at 20 C is a20 and the temperature coefficient for conductivity C at t C is aCt aCt is determined as follows near the ambient temperature For example the temperature coeffi...

Page 80: ...to determine temperature increase as follows Example With resistance R1 of 200m at initial temperature t1 of 20 C and measured resistance R2 of 210 m at current ambient temperature t2 of 25 C the tem...

Page 81: ...nual Edition V1 0 81 For example the temperature coefficient of copper at 20 C is 3930 ppm C so the constant k in this case is as follows which shows almost the same value as the constant for copper 2...

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