41– 42, 76, 78

M

Magnetic Loops Noise, 28

Making Multimeter Measurements, 53– 56 externally triggered measurements, 54 maximizing accuracy, 56 maximizing speed, 55 measurement format, 54

single measurements, 54 using FETCh? command, 53 using INITiate commands, 53 using MEASure commands, 53 using READ? command, 53

Math Operations, 41– 44 AVERage function, 41, 74, 76 dB measurements, 42– 43, 75– 76 dBm measurements, 43, 75– 76 LIMit function, 44, 76– 77 NULL (relative) function, query function, 76

Maximum accuracy, 56

average operation value, 74 current, 15 measurement speed, 55 voltage, 15

MEASure Subsystem, 101– 110 MEAS:CURRent:AC?, 102 MEAS:CURRent:DC?, 103 MEAS:FREQuency?, 104 MEAS:FRESistance?, 105 MEAS:PERiod?, 106 MEAS:RESistance?, 107 MEAS:VOLTage:AC?, 108 MEAS[:VOLTage[:DC]]?, 109 MEAS[:VOLTage[:DC]]:RATio?, 110

Measurements

2-wire ohms connections, 21, 30

4-wire ohms connections, 21, 29 ac below full scale, 34

ac current characteristics, 175 high speed, 36

ac voltage characteristics, 175 high speed, 36

loading errors (ac volts), 34 configuration, 37– 40

ac signal filter, 37, 127– 128 autozero, 40

integration time, 39 ranging, 40

Measurements (continued)

configuration (continued)

resolution, 38 current connections, 22 dB, 42– 43, 75

dBm, 43, 75 dc current

characteristics, 172 errors, 32

dc voltage, 25– 28 characteristics, 172

common mode rejection (CMR), 27 ground loops noise, 28

high speed, 31

leakage current errors, 26 loading errors (dc volts), 26 magnetic loops noise, 28 ratio, 95, 110

rejecting power line noise voltages, 27 thermal EMF errors, 25

error, 180– 181

frequency characteristics, 177 frequency connections, 19 functional connections, 19– 22 high accuracy, 184

making, 53– 56

externally triggered measurements, 54 maximizing accuracy, 56, 193– 198 maximizing speed, 55, 193– 198 measurement format, 54

single measurements, 54

using FETCh? command, 53, 98, 198 using INITiate commands, 53 using MEASure commands, 53 using READ? command, 53

period characteristics, 177 period connections, 19 resistance, 29– 31

2-wire ohms, 30

4-wire ohms, 29

high resistance measurement errors, 31 high speed measurements,

power dissipation effects, settling time effects, 31

retrieving from memory, 98

speed and accuracy tradeoffs, 193– 198 temperature measurement resistors, 31 true RMS ac, 32– 35

tutorial, 25

voltage connections, 20

voltage ratio (Vdc) connections, 20

Index 205