I have a Uni-T UT61E multimeter and it comes with some accessory (middle picture) to make it easier to assess certain electrical components but it doesn't use the COM port; it uses two ports that the red cable normally gets plugged into and it gives higher resistance in this port. Is this higher resistance a sign of damage to the meter?

 

You should read the manual.
You cannot use mA/uA port to measure resistance.
To measure resistance, Voltage and all other except current , you should use the COM and RED port.
The 10A, and mA/uA port is ONLY ( repeat ONLY ) used for Current (I) measurements.

 

"u r doing it wrong."

 

What are you trying to measure with the connection on the right?
That connection to the inputs (ports are for computers) is not defined as a valid measurement connection.
Likely you are measuring the resistance of the current shunt along with the resistor.
The COM input is used for all measurements.

 

You all seem to be ignoring the accessory which is marked with an R and a C and it plugs into the mAuA socket. There is no way to plug it into the COM socket; it's made of hard plastic. It's the only way to use the accessory and the mAuA socket works fine for measuring capacitance with this accessory.

 

That adapter is a K-type thermocouple adapter. See here: www.omega.com/pptst/5LSC_5SRTC.html for examples of the two types of plugs. One has a round terminals and the other flat. K-type is yellow coded.

If the terminals are shorted you should read room temperature There may be a small battery inside the device,

It could work differently than that, by just being an isothermal block and the meter has ersatz cold-junction compensation.

Try the mV scale with a shorted input (where you have the resistor).

K is written on the unit and I think it has the right spacing for the two major types of thermocouple connectors,

These www.omega.com/pptst/OST.html are the big ones.

These http://www.omega.com/pptst/NMP.html are the smaller ones.

This http://www.testpath.com/Items/Therm...d-Banana-Plug-to-K-Type-Connector-116-130.htm adapter might be like yours where it's just an isothermal connector. The DVM measures the ambient temperature and compensates the thermocouple.

There can be offset voltages generated because of the different metals used.

 

It looks as though the difference can be the added resistance of your test leads -about 1 ohm. It seems high but I have some cheap test leads that approach that resistance. Short your probes together and see what resistance the meter displays, if it reads near an ohm, the test leads are the problem.

 

Model UT61A/61B/61C/61D/61E: OPERATING MANUAL covers all of the measurement setups.

Page 21 of the above link:
C. Measuring Resistance
Warning To avoid damages to the Meter or to the devices under test, disconnect circuit power and discharge all the high-voltage capacitors before measuring resistance. To avoid harm to yourself, do not input higher than DC 60V or AC 30V voltages. To measure resistance, connect the Meter as follows:
1. Insert the red test lead into the terminal and the black test lead into the COM terminal.
2. Set the rotary switch to resistance measurement ( ) is default or press BLUE button to select measurement mode.
3. Connect the test leads across with the object being measured. If there is lead on the resistor or SMT resistor, it is more convenience to use the included multi- purpose socket to carry out testing.The measured value shows on the display.

Page 23 covers lead resistance. Figure 4 on page 21 shows the setup with and without the added fixture for resistance measurements. So what is the problem? Your image on the left would be correct. I have no idea why the center image reads as it does. What is the resistance of that little test resistor you are using?

Ron

 

Model UT61A/61B/61C/61D/61E: OPERATING MANUAL covers all of the measurement setups.

Page 21 of the above link:
C. Measuring Resistance
Warning To avoid damages to the Meter or to the devices under test, disconnect circuit power and discharge all the high-voltage capacitors before measuring resistance. To avoid harm to yourself, do not input higher than DC 60V or AC 30V voltages. To measure resistance, connect the Meter as follows:
1. Insert the red test lead into the terminal and the black test lead into the COM terminal.
2. Set the rotary switch to resistance measurement ( ) is default or press BLUE button to select measurement mode.
3. Connect the test leads across with the object being measured. If there is lead on the resistor or SMT resistor, it is more convenience to use the included multi- purpose socket to carry out testing.The measured value shows on the display.

Page 23 covers lead resistance. Figure 4 on page 21 shows the setup with and without the added fixture for resistance measurements. So what is the problem? Your image on the left would be correct. I have no idea why the center image reads as it does. What is the resistance of that little test resistor you are using?

Ron

The lead resistance is 0.15 ohm and is not the problem.

The resistance of the test resistor is 5.54 ohms according to my DMM (1st image, 5.69 ohm - 0.15 ohm from leads).

The problem is that when I use the "multi-purpose socket" (previously referred to as "the accessory"), the resistance given is markedly higher.

To determine whether this was caused by the multi-purpose socket or the DMM itself, I compared the value I get with the multi-purpose socket (second image) with the value I get from the leads plugged into the same terminals that the multi-purpose socket is plugged into (third image).

 

Hello,

Looking at the UNI-T website, the adapter is suitable for the UT61B, UT61C and UT61D.
http://www.uni-trend.com/productsdetail_966_847_847.html
Your meter UT61E is not mentioned on that page.

The manual mentiones the adapter on the pages 21 and 29.
They mention to use the select button.

Bertus

 

Did you read the user's manual?

Your test resistor appears to be 4.7Ω.

Use RELΔ when measuring below 2kΩ.

 

Did you read the user's manual?

Your test resistor appears to be 4.7Ω.

Use RELΔ when measuring below 2kΩ.

I can subtract 0.15 ohm in my head. It does not account for the 20 ohm difference when using the multi-purpose socket.

Yes I've read the manual. The manual does not say I'm doing anything wrong.

Hello,

Looking at the UNI-T website, the adapter is suitable for the UT61B, UT61C and UT61D.
http://www.uni-trend.com/productsdetail_966_847_847.html
Your meter UT61E is not mentioned on that page.

The manual mentiones the adapter on the pages 21 and 29.
They mention to use the select button.

Bertus

The UT61E came with this accessory in the box and it works fine for measuring capacitance.

Thanks but I don't need to use the select button. If I used it, I'd need to use it two more times to get back to the default mode.

 

The 20Ω difference comes from using the mAμA socket instead of the COM socket.
Use RELΔ as the User Manual says.

 

I said it in the first place and yet OP refuses to do as explained.

 

Get another meter and measure the resistance between the mAμA socket and the COM socket.
Don't be surprised if you read about 20Ω or a little more because of the resistance of your test leads.

 

The 20Ω difference comes from using the mAμA socket instead of the COM socket.
Use RELΔ as the User Manual says.

You can't use RELΔ with the multi-purpose socket because there's no way to short the pads without using an external piece of wire. I'm pretty sure it's just intended for the leads.

I realise that the 20 ohm difference comes from using the mAuA socket and that's why I'm posting; I want to know whether all UT-61Es are the same as mine or if mine is damaged and giving a higher resistance.

 

Looking at this again and reading the manual I tend to agree something isn't right using the fixture (accessory).

Figure 4 right from the manual:


To measure resistance, connect the Meter as follows:
1. Insert the red test lead into the terminal and the black test lead into the COM terminal.
2. Set the rotary switch to resistance measurement ( ) is default or press BLUE button to select measurement mode.
3. Connect the test leads across with the object being measured. If there is lead on the resistor or SMT resistor, it is more convenience to use the included multi- purpose socket to carry out testing.The measured value shows on the display.

Possibly the fixture has an issue. I guess you could just use leads (the standard meter leads and take a few resistance measurements between the pins on the fixture where it plugs into the meter and the measuring plane where the part leads connect. That may tell you something about the fixture.

Ron

 

I do not think any one care about here the "accessory" is plugging in.
We all know what yuo are doing is wrong and still you refuse to believe us.

OP is not doing it wrong. The meter is lying to the OP. There is a 20Ω current shunt in the meter from mAμA socket to the COM socket.

 

You cannot measure R from the current ports. The shunt resistance will add up. So he is doing it wrong or that is the wrong "accessory"

 

You can't use RELΔ with the multi-purpose socket because there's no way to short the pads without using an external piece of wire. I'm pretty sure it's just intended for the leads.

I realise that the 20 ohm difference comes from using the mAuA socket and that's why I'm posting; I want to know whether all UT-61Es are the same as mine or if mine is damaged and giving a higher resistance.

That is how you use the RELΔ button.
Step 1. Short the input connections.
Step 2. Press RELΔ.
Step 3. Remove the short and continue to do your resistance measurement. This will subtract the "zero" error.

That is the way the meter is designed to be used. There is nothing wrong with the meter.