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Hi everyone, i just bought a used HP3468B(no manual no test leads) on ebay and i was wondering if there was a way to automatically subtract the test leads resistance from the reading ? Thanks

Operator's Manual

Service Manual

What is the connection to HP calcs?

tm

HPIL. This multimeter is HPIL-accessible, so an HP41 can be used to control it.

Along with many other measuring devices, HP added either HPIL or HPIB as comm standard. The HP3421 is another example: a data acqusition 'center' with HPIL option. There is a specific ROM for the HP41 that adds many specific data acquiring features, and this ROM is supposed to be used to help controlling the 3421.

Cheers.

Luiz (Brazil)

Indeed, this device is *so* linked with HP-IL and especially the 41C that page #2 of the Operator's Manual shows a 41C program to control it, most of the manual is dedicated to calculator programming using the 41C and the 85. The 3468A/B has been discussed here before several times and the brochure for it is included on this site's CD/DVD documentation.

Ah the 3468B! Was my dream DMM. I had good luck using the 48SX and GX with a Fluke 45. I tried the 48 with the Fluke 189 but could not get it to work.

Thanks everyone for your quick response greatly appreciate.

I dont have a HP41 or anything to control 3468, is there another way subract the test lead resistance. Sorry if i sound stupid im new to this stuff. Thanks

For some time I have been acquiring some test equipments, like oscilloscopes, multimeter, frequency counter, and other, but all with HP-IL or HP-IB interfaces.

For last, I got one IOtech RS232-HPIB interface equipment.

So, I mounted the following circuit:

HP41 ---> (hp-il) ---> HP3468A (dmm) ---> HP 81162a (printer) v

^-- HP-IL/HP-IB interface <-- HP 82161A (cassette) <----------|

      |                     \

HP 54503A (oscilloscope)    |

HP 5385A  (freq.counter)    |

HP 54506A (relay actuator)  | ===== HP-IB circuit

      |                     |

 other equipments           |

      |                     |

  IOtech  HPIB/RS232 (x4)   /

  |          |        |                  \

  |          |        |                  | RS232 circuit

HP-48GX   computer    other rs232 device / 

By now, I could send/receive data and programs from HP41 to 48GX, but I really would like to control and get data from test equipments from/on my 48GX, using its soft menu system.

Has anybody ever tried this out?

Best regards

Artur

Edited: 31 July 2006, 2:48 p.m.

What are you measuring, micro-Ohms? Why is the test lead resistance a factor? Can't you just short them and zero the meter?

Edited: 31 July 2006, 4:54 p.m.

Hi, Max

I believe there is no way to take a measuring completely excluding the resistance from leading points.
The best you can do is to use the 4 Wire connection for small resistances, when the leading resistance shall be almost unconsidered.
You can read about this in the User's Guide.
Artur

I don't have one of these DMM's but the manual talks about an autozero function for 4-wire ohms measurements (page 9) and says that the autozero function does subtract out the lead resistance. I wonder why they didn't do this in 2-wire mode? I'm I just misreading the manual?

katie, it simply doesn't make much sense to subtract wire-resistance in 2-wire measurements. this is because of the nature of the test tips (or, clips). the direct connecting between the tips and the d.u.t. is simply not reproducible in most cases and therefore almost always influences the measurement in an unpredictable way. if lead resistance is *really* getting of concern, because the resistance of the d.u.t. is in the range where lead resistance would falsify the readings, 4-wire measurement is the way to go.

cheers,
hans

Mr Duell did something with it... search via google...sorry I had information but not here...