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General => General Discussion => Topic started by: USMCPMEL on 05-01-2012 -- 21:31:00

Title: how much better is the 5720A than the 5700?
Post by: USMCPMEL on 05-01-2012 -- 21:31:00
any know directly?
Title: Re: how much better is the 5720A than the 5700?
Post by: John Treekiller on 05-02-2012 -- 05:33:39
I'm an AF K1 and K8 (DC and Low Freq) tech writer and have written procedures for both and using both as stds.  It really depends on usage.   The AF has many General DMM CTOs that were written before the 5720A was manufactured and the 5700A specs are fine  for use with these DMMs.  Some of the equipment recently acquired by the AF requires the better specs of the 5720A for calibration.  Both Models have the same WB option and both use the 5725A Amp for expanded Amps and ACV capability. So the spec improvement is basically for DC and low freq AC.  A lot of the 5700As in the inventory have had the upgrade option installed by Fluke during various repairs.
Title: Re: how much better is the 5720A than the 5700?
Post by: jimmyc on 05-02-2012 -- 07:46:51
Voltage DC Ranges:  0 to ±1100V
5700A Best 1 Year Specification:  ±7.0 ppm of setting
5720A Best 1 Year Specification:  ±3.5 ppm of setting

Voltage AC Ranges:  220 mV to 1100V
   10 Hz to 1 MHz
5700A Best 1 Year Specification:  ±75.0 ppm of setting
5720A Best 1 Year Specification:  ±45.0 ppm of setting

Resistance Ranges:  0 to 100 MΩ, 18 values in x1 and x1.9
5700A Best 1 Year Specification:  ±12.0 ppm
5720A Best 1 Year Specification:  ±8.5 ppm

Current DC Ranges:  0 to ±2.2A (11A with 5725A)
5700A Best 1 Year Specification:  ±50 ppm of setting
5720A Best 1 Year Specification:  ±35 ppm of setting

Current AC Ranges:  9 mA to 2.2A (11A with 5725A) 10 Hz to 10 kHz
5700A Best 1 Year Specification:  ±140 ppm of setting
5720A Best 1 Year Specification:  ±120 ppm of setting

Wideband AC Voltage Option Ranges:  300 mV to 3.5V
   10 Hz to 30 MHz
5700A Best 1 Year Specification:  ±0.4% of setting
5720A Best 1 Year Specification:  ±0.4% of setting

Title: Re: how much better is the 5720A than the 5700?
Post by: USMCPMEL on 05-02-2012 -- 08:06:12
Well that seems pretty good. Wonder what the price difference is? I saw one on ebay for $52k.
Title: Re: how much better is the 5720A than the 5700?
Post by: retiredAFinSD on 05-02-2012 -- 09:09:04
You can find the 5700A on used-line from $18k to $24K and get it converted by Fluke to the 5720A , for an additional $17k, I think. Also check used-line for the 5720A.
Title: Re: how much better is the 5720A than the 5700?
Post by: spanishfly25 on 05-02-2012 -- 09:26:52
5720 is also better when calibrating temperature meters that use Thermocouple sensors, like type K, J and T TCs
Title: Re: how much better is the 5720A than the 5700?
Post by: metrologygeek on 05-02-2012 -- 12:36:16
I think you might be thinking about the 5520, unless you're using external cold junction compensation and tables.
Title: Re: how much better is the 5720A than the 5700?
Post by: yonker08 on 05-02-2012 -- 12:48:49
Quote from: USMCPMEL on 05-02-2012 -- 08:06:12
Well that seems pretty good. Wonder what the price difference is? I saw one on ebay for $52k.

If you want to take the chance sometimes I see them pop up on http://www.govliquidation.com/. The ones I've seen went for less then 5K$.
Title: Re: how much better is the 5720A than the 5700?
Post by: WestCoastCal on 05-02-2012 -- 14:40:02
Attached is a datasheet for the 5700A, 90 day, 99% confidence level, absolutes.  I added the 5720A (90 day, 99%, absolutes) as the calibration standard.  The TARs listed display the ratios between the 5700A and 5720A.  For example, if the TAR is 1.3:1, this means the 5720A is 30% more accurate than the 5700A. If the TAR is 1.0:1, then the instruments are equal in accuracy. I did not find any instances where the 5700A is more accurate then the 5720A.  I probably made a couple wrong associations, it is for demonstration only.
Title: Re: how much better is the 5720A than the 5700?
Post by: USMCPMEL on 05-03-2012 -- 09:29:10
Thanks for all the input.
Title: Re: how much better is the 5720A than the 5700?
Post by: USMCPMEL on 05-03-2012 -- 09:30:51
Quote from: yonker08 on 05-02-2012 -- 12:48:49
Quote from: USMCPMEL on 05-02-2012 -- 08:06:12
Well that seems pretty good. Wonder what the price difference is? I saw one on ebay for $52k.
Really? wow for 5k I would buy one to start up a business on the side lol

If you want to take the chance sometimes I see them pop up on http://www.govliquidation.com/. The ones I've seen went for less then 5K$.
Title: Re: how much better is the 5720A than the 5700?
Post by: measure on 05-03-2012 -- 12:50:16
Quote from: WestCoastCal on 05-02-2012 -- 14:40:02
Attached is a datasheet for the 5700A, 90 day, 99% confidence level, absolutes.  I added the 5720A (90 day, 99%, absolutes) as the calibration standard.  The TARs listed display the ratios between the 5700A and 5720A.  For example, if the TAR is 1.3:1, this means the 5720A is 30% more accurate than the 5700A. If the TAR is 1.0:1, then the instruments are equal in accuracy. I did not find any instances where the 5700A is more accurate then the 5720A.  I probably made a couple wrong associations, it is for demonstration only.
Obviously, you made some "wrong associations." The 5720A is, except for Wideband and 5725A 'Boost' outputs, almost universally more accurate (substantially, in many cases) than the 5700A. A quick perusal of the specifications (available at www.flukecal.com) will confirm any doubters. Which one is 'best' depends on the workload and accuracy requirements that are being addressed in a specific lab, keeping in mind capital acquisition costs.
Title: Re: how much better is the 5720A than the 5700?
Post by: yonker08 on 05-03-2012 -- 13:37:50
Quote from: USMCPMEL on 05-03-2012 -- 09:30:51
Quote from: yonker08 on 05-02-2012 -- 12:48:49
Quote from: USMCPMEL on 05-02-2012 -- 08:06:12
Well that seems pretty good. Wonder what the price difference is? I saw one on ebay for $52k.
Really? wow for 5k I would buy one to start up a business on the side lol

If you want to take the chance sometimes I see them pop up on http://www.govliquidation.com/. The ones I've seen went for less then 5K$.
Of course that doesn't include transportation costs and sending it out for an up to date calibration. I'm about an hour away from one of the centers so that makes it easier.