| ??? 06/11/05 09:52 Read: times |
#94673 - Where are the problems, concretely? Responding to: ???'s previous message |
Ant said:
But my problem is that the current and voltage measurements i need to measure to calculate the resistance. they are only to 1 decimal place but i need to be able to calculate the resistance to 2 decimal places. can anyone give me a clue on how i can get around this? I'm not quite sure, where your problem is. Normally, you use a precision current source, where there's then no need for an additional current measurement. You take only the voltage drop across PT100 into consideration and calculate from this the temperature. But if you want to measure current and voltage, where is your problem? You can very easily measure the current, by monitoring the according voltage drop across a very high precision resistor. Take a good OPamp with very high precision resistors in the feedback loop, then you can precisely measure the current. The same for the voltage drop across PT100. Or do you use ready made multimeters for the measurement? Please elaborate a bit, where you get the problems. Kai |
| Topic | Author | Date |
| making a pt100 thermometer using a 8051 | 01/01/70 00:00 | |
| you are usually better off | 01/01/70 00:00 | |
| current sources | 01/01/70 00:00 | |
| TI (Burr-Brown) App Note SBAA050 | 01/01/70 00:00 | |
| That's great | 01/01/70 00:00 | |
| ads574 | 01/01/70 00:00 | |
| Indeed a very good link! | 01/01/70 00:00 | |
| calculating resistance | 01/01/70 00:00 | |
| Where are the problems, concretely? | 01/01/70 00:00 | |
| measuring resistance | 01/01/70 00:00 | |
| Use better mulitmeter... | 01/01/70 00:00 | |
| 2 multimeters | 01/01/70 00:00 | |
| max1410 | 01/01/70 00:00 | |
| Theoretical curve | 01/01/70 00:00 | |
| PT100 | 01/01/70 00:00 | |
| pt100s | 01/01/70 00:00 | |
| Look at LT1001data sheet | 01/01/70 00:00 | |
| wheatstone bridge | 01/01/70 00:00 | |
| Look at it this way..... | 01/01/70 00:00 | |
| anyone knows | 01/01/70 00:00 | |
| Keep it simple... | 01/01/70 00:00 | |
| So does Maxim | 01/01/70 00:00 | |
Already done... | 01/01/70 00:00 |