Current Clamp readings.

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narmour

Current Clamp readings.

Post by narmour » Tue Nov 02, 2004 3:40 am

We have been using a current clamp to measure the current delivered from a current source. Our setup is your 60Amp current clamp connected to the ADC212 oscilloscope. The problem is the readings from the current clamp. Over a 72hr monitoring period, the read current decays approximately 0.8amps in a roughly linear fashion. The current from the source has been verified at a steady 13.6Amps, while the current clamp reading varies. Any help with this would be much appreciated, also what are the tolerances on the readings from the current clamp?

Thank You

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markspencer
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Post by markspencer » Tue Nov 02, 2004 11:26 am

Hi,

I am sorry to hear that you are experiencing this problem. What voltage to range are you using it on and is it DC or AC.

The tolerances are as follows:

DCA range: 1mV/10mA
±(1.5% ±5mA) 10mA ~ 20A

DCA range: 1mV/100mA
±(2% ±20mA) 100mA ~ 40A
±(4% ±0.3mA) 40mA ~ 60A

ACA range: 1mV/10mA
±(2% ±5mA) 10mA ~ 10A (40Hz - 2kHz)
±(4% ±30mA) 10mA ~ 10A (2kHz - 10kHz)
±(6% ±30mA) 10mA ~ 10A (10kHz - 20kHz)
±(8% ±30mA) 10mA ~ 15A (40Hz - 20kHz)

ACA range: 1mV/100mA
±(2% ±30mA) 100mA ~ 40A (40Hz - 1kHz)
±(4% ±30mA) 100mA ~ 40A (1kHz - 2kHz)
±(6% ±30mA) 100mA ~ 40A (3kHz - 5kHz)
±(8% ±0.3mA) 40mA ~ 60A (40Hz - 5kHz)

The CA-60 Current clamp is also battery operated, it is possible that the signal may decay as the battery is used.

Best regards,
Regards,

Mark Spencer

narmour

Voltage Range

Post by narmour » Tue Nov 02, 2004 8:04 pm

The voltage range is 2V DC. To alleviate the battery problem we have switched to a 9V DC transformer replacing the battery. It seems the base line is moving. We zero the current clamp at the beginning of a recording run, but by the end it has built up a relatively large, 1.4A, negative reading.

narmour

TA009

Post by narmour » Tue Nov 02, 2004 8:10 pm

Just to make sure, our current clamp part number is TA009.

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markspencer
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Post by markspencer » Fri Nov 05, 2004 8:31 am

Hi,

Thank you for the extra information, I will try to replicate this by repeating what you have said and let you know the results ASAP. Unfortunately, it will take a while, as I want to test it for the period you are using yours for.

The voltage range you have specified is the one on being used on the ADC-212, but which Voltage to Amp are you using.

Best regards,
Regards,

Mark Spencer

narmour

Post by narmour » Thu Nov 11, 2004 10:42 pm

We are using the 10mA/mV setting

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