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elektroda.net NewsGroups Forum Index - Electronics Equipment - **FET voltmeter sought**

Guest

Sat Mar 12, 2016 10:53 pm

Suppose a fellow wished to buy a high input impedence voltmeter rather

accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

Guest

Sat Mar 12, 2016 11:31 pm

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

Best regards

Reinhard

Guest

Mon Mar 14, 2016 6:40 pm

Reinhard Zwirner wrote:

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

Best regards

Reinhard

Guest

Mon Mar 14, 2016 7:06 pm

On 03/14/2016 08:40 AM, Peter Percival wrote:

Reinhard Zwirner wrote:

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

A 50 M precision series resistor (probably a series combination),

measuring on the microamp range. You have 1 pA resolution there, which

is 100 uV. You do have to watch the burden voltage, of course.

Cheers

Phil

Guest

Mon Mar 14, 2016 7:19 pm

Phil Hobbs wrote:

On 03/14/2016 08:40 AM, Peter Percival wrote:

Reinhard Zwirner wrote:

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

A 50 M precision series resistor (probably a series combination),

measuring on the microamp range. You have 1 pA resolution there, which

is 100 uV. You do have to watch the burden voltage, of course.

Cheers

Phil

Thank you.

Reinhard Zwirner wrote:

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

A 50 M precision series resistor (probably a series combination),

measuring on the microamp range. You have 1 pA resolution there, which

is 100 uV. You do have to watch the burden voltage, of course.

Cheers

Phil

Thank you.

Guest

Mon Mar 14, 2016 7:39 pm

On Sat, 12 Mar 2016 15:53:37 +0000 Peter Percival

<peterxpercival_at_hotmail.com> wrote in Message id:

<nc1e25$eli$2_at_news.albasani.net>:

Suppose a fellow wished to buy a high input impedence voltmeter rather

accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

If you want fairly cheap:

HP 3478A has an input impedance of >100Gohm on it's 3VDC or less ranges.

HP 3456A has an input impedance of >100Gohm on it's 10VDC or less ranges,

but size is a bit large.

Guest

Sat Sep 24, 2016 5:25 pm

On 3/14/2016 7:40 AM, Peter Percival wrote:

Reinhard Zwirner wrote:

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

Best regards

Reinhard

Peter Percival schrieb:

Suppose a fellow wished to buy a high input impedence voltmeter

rather accurate for low voltages (< 10v, say) but not expensive. Any

recommendations?

What do you mean with "high"? Digital multimeters normally have an

input impedance of 10 MOhms; the lowest measuring range is 0.2 volts.

50 Mohms down to 0.01 volts. Is that too much to ask?

Best regards

Reinhard

You could put a 40M resistor in series and divide the reading by 5.

0.002V x 5 = 0.01V So, I guess you would need a 4-1/2 digit multi meter.

Or is that 3-1/2?

Mikek

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