Test & Measurement

Gm8juy · Post by **Gm8juy** » Tue Jun 17, 2003 3:22 pm

Hi guys, I am looking for equipment to allow the simultaneous measurement (or separate measurement on occassions) of single or 3 phase voltage, current consumption, kilowatt hours, power factor and, wait for it, possibly pressure and temperature from two sources at once.

Sounds a lot but it is to allow environmental testing on water & steam generation equipment.

I currently use an ADC 11 for temperature & pressure measurements.

Some anticipated limits :-
Voltage 440 ac : Current 30 amps 1 phase / 3 phase
Temperature < 140 deg. C. : Pressure < 2 bar

Thanks in anticipation

Bob

markspencer · Post by **markspencer** » Thu Jun 19, 2003 10:43 am

Hi,

If you are using Picolog to take these measurements you can use multiple convertors.

To measure the Temperature and Pressure you could continue using the ADC11. To then measure the current and Voltage you can use an ADC-100. If you need more than two cannels, for these measurements, which is most likely, you will have to purchase the appropriate number of units.

In addition to these units to measure the voltage of 440 volts you will need to use an isolating probe (fro safety) such as the x10/x100, one for each phase.

The current can be measured using a 60A AC/DC current clamp.

Unfortunately, it is not possible to measure KWatts per hour or power factor.

Best regards,

Guest · Post by **Guest** » Thu Jun 19, 2003 10:55 am

Thanks Mark, I am probably looking to ditch the ADC11 and buy something more versatile and up to date. The other drawback of the ADC11 is its inability to go below zero, thus creating problems measuring AC waveforms.
It may be necessary to purchase equipment to measure the voltage & current functions separate from the pressure & temperature, what do you think?

Regards and thanks

Bob

markspencer · Post by **markspencer** » Thu Jun 19, 2003 11:29 am

Hi,

The only data logger that we have that has more than one channel and will measure bipolar voltage is the ADC-16. This will measure ±2.5 volts. However, it is a high resolution and designed for accuarcy rather than speed, so it would depend on the sample rate you want, since it has a sampling rate of 1.5Hz. If this is OK you could use it to measure
temperature and presure.

If you want a seperate unit to measure temperature the unit you would need is dependent on accuracy, temperature range and resolution.

If you are going to ditch the ADC-11 only because you cannot measure bipolar then a possible solution for this would be to use an offset. If you place a voltage on the input line equvilent to the offset you want then this would allow negative rail to be measured. ie. if a 0 voltage was on the input line to the ADC11 channel and you add 1.2 volts to the this by putting a voltage in series then the voltage will read 1.2 volts. Therefore if you put -1.2 volts in and again the offset is 1.2 volts then the voltage would read 0 volts. You can then use a scaling file.

Best regards,