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Since its release in 1990, the 5790A has developed an unmatched
reputation of being the most precise ac measurement standard in the
industry. The technology behind the 5790A and the patented Fluke
RMS sensor has made it the measurement standard of choice for
calibration laboratories around the world. The 5790B retains the
innovative technical features of its predecessor and adds many new
capabilities and functions which expand the capable workload and
reliability of the product.
The Fluke A40B series shunt resistors provide a very cost effective
method to expand the 5790B’s functionality to measure absolute and
relative ac current to calibrate an ac current source. The 5790B's
new user interface allows you to input and save current shunts to
its memory. Up to 150 shunts can be stored along with the shunts’
serial numbers, calibration constant values (24 ac/dc, five loading
error points) and calibration dates. After the shunt information is
loaded, the 5790B can be set up to take a direct absolute or
relative ac current measurement within seconds by hooking up the
shunt and simply selecting the appropriate shunt from the main
menu. When using a current shunt, 5790B displays both the voltage
and current measurements on the display along with the shunt
information. Legacy Fluke A40 and A40A current shunts can be loaded
and used to make relative current measurements.
The “/3” wideband input and function, with ranges of 2.2 mV to 7 V,
10 Hz to 30 MHz, is retained from the 5790A model. A new “/5”
wideband option extends the bandwidth even further, to 10 Hz to 50
MHz. The expanded wideband range extends the workload of the
product to calibrate precision 50 MHz power reference outputs found
on most RF power meters.
A direct-readout-mode graphical user interface displays
specifications for measuring common non-sinusoidal waveforms plus
peak-to-peak computation (assumes THD <1 %.) This allows for
instantaneous information when it is needed the most. Unlike the
vacuum-fluorescent display on the 5790A, the new 6.5-inch
capacitive touch screen display allows you to see more information
on screen, reducing the need to switch between menus. The 5790B now
specifies absolute dc voltage measurement uncertainties as low as ±
24 ppm (one year, 23 °C ± 5 °C), providing more confidence in
transfer measurements. A dedicated special purpose 50 MHz, 225 mV,
50 ohm input function is available as an option for measuring RF
power meter power reference outputs. The option is “spot
calibrated” at the end of a precision level/phase stable metrology
grade cable. It calculates the measured power with a 50 ohm load.
Statistics showing number of samples, standard deviation, average,
min and max are calculated using the displayed readings as the
basis. As a benefit of the large touch screen display, the
statistics data can be viewed while the main measurement is still
visible on the screen. The 5790B now does peak-to- peak waveform
calculations for you. You can select one of four waveforms: sine,
square, triangle, and truncated. Some of these waveforms are
difficult and time consuming to calculate. The 5790B performs all
the calculations for you based on the measurement, significantly
reducing time and possible errors.
The graphical user interface features easy-to-read menus, as well
as access to common functions with just the touch of a finger.
Quickly select the range and input using the hard keys on the front
panel. A bright red status indicator for HAZARDOUS VOLTAGE is
located on front panel, letting you know immediately when hazardous
voltage is present at the terminals. Like the new 5730A Multi-
Product Calibrator, the front panel features Visual Connection
Management™ terminals that light up to show you which terminals are
active, guiding you to make the correct connections.
The 5790B is based on the patented Fluke Solid-State Thermal RMS
Sensor, which has been proven since 1979 in a variety of Fluke
products like the 792A AC/ DC Transfer Standard. The Fluke RMS
Sensor is a true thermal converter, not an electronic converter
that calculates the RMS value. Because its output voltage is 2 V
rather than the 7 mV to 10 mV of traditional thermocouples, the RMS
sensor exhibits excellent signal-to-noise characteristics and
minimal reversal errors. With a higher output voltage, more
accurate measurements can be made. And because of its small size,
the RMS sensor stabilizes quickly and operates over a wide
temperature range. The 5790B also features hermetically sealed
thin-film resistor networks to minimize ac measurement errors and
enhance temperature coefficient. The RMS sensor and thin-film
resistor networks are designed by Fluke to be rugged and reliable.
Each is built to exacting standards by the Fluke Microelectronics
Group to maintain quality and consistency part after part.
The variety of inputs and connection types allows you to use the
one that best suits your application. There are four sets of input
terminals on the 5790B, two Type-N connectors and a set of five-way
binding posts. One Type-N and one set of binding posts are
dedicated to the ac measurement and transfer modes. AC or dc
voltages may be applied to either input connection over the 5790B’s
full range, allowing you to perform automated ac/dc transfer
measurements. The 5790B determines automatically whether the
applied voltage is ac or dc.
The second Type-N input connection supports the optional wideband
mode. The input connection is easily selected with the touch of a
key on the 5790B front panel. An LED indicates which terminals are
active.
Whether you are using the 5790B as a voltmeter or a transfer
standard, input voltage and frequency are always indicated on the
measurement display. In the transfer mode, the ac/dc or ac/ac
difference is always indicated on the control display in ppm, %,
volts or ratio.
The 5790B is a fully autoranging instrument and it selects the best
voltage range for the measurement you are making. You may also
select and lock in ranges manually. Robust 1200 V input protection
is active on all voltage ranges.
Using the trigger keys, the 5790B can switch from continuous to
single measurements of the input voltage, making it easy to take
sample readings at predetermined intervals.
When using the 5790B in transfer mode, the reference voltage is
stored, and all ac/dc or ac/ac difference measurements are made
relative to it. You may also store the average of two voltages as a
reference to eliminate dc reversal errors, for example.
The intuitive front panel layout of the 5790B makes manual
operation fast and simple. Keys and selections are logically
arranged and labeled. And messages and menus are displayed clearly
on the 5790B’s bright, touch screen display display.
USB, GPIB/IEEE-488, Ethernet and RS-232 interfaces are included and
all functions of the instruments can be controlled by a PC. Using
an available instrument driver, the 5790B can be integrated into
automated systems operating with MET/CAL® Calibration Software.
Summary Specifications | |
AC and dc voltage | Best 99%, absolute specification: ± 24 ppm (one year, 23 °C to ± 5 °C |
Inputs | Input 1: 600 µV to 1000 V (5% over-range) Input 2: 600 µV to 1000 V (5% over-range) Aux input: 250 mV to 500 mV WB input: <7 V rms wideband |
Warm-up time | 30 minutes |
Relative humidity | Operating: 45% to 50 °C 75% to 45 °C 95% to 30 °C Storage: <95% non-condensing |
Altitude | Operating: 3,050 meters (10,000 feet) Non-operating: 12,200 meters (40,000 feet) |
Temperature | Operating: 0 °C to °50 C Calibration: 15 °C to 35 °C Storage: -40 °C to 70 °C |
Electromagnetic Compatibility (EMC) | |
International | IEC 61326-1: Controlled Electromagnetic Environment - CISPR 11: Group 1, Class A |
Korea (KCC) | Class A Equipment (Industrial Broadcasting & Communication Equipment) |
USA (FCC) | 47 CFR 15 subpart B. This product is considered an exempt device per clause 15.103. |
Surge | ANSI C62.41-1980, Category A |
Reliability | MIL-T-2880D, paragraph 3.13.3 |
General Specifications | |
Dimensions | Height: 17.8 cm (7 in) standard rackmount + 1.5 cm (0.6 in) Width: 43.2 cm (17 in) Depth: 62 cm (24.8 in) |
Maximum power requirements | 5790B: 100 VA |
Weight | 5790B: 24 kg (53 lb) With wideband: 24.5 kg (54 lb) |
Line power | 50 Hz or 60 Hz; 100 V - 120 V, 220 V - 240 V 100V, 110 V, 115 V, 120 V, 200 V, 220 V, 230 V, 240 V |
Safety | Complies with UL1244 and IEC 348-1976 and IEC 1010 and CSA C22.2 No. 231 and ANSI/ISA S82 |
Remote interfaces | RS-232, IEEE-488 |
Confidence level | 99% unless otherwise specified |
5790B/AF | |
The 5790B/AF has enhanced absolute accuracy to ± 0.23 % of voltage (1 year after factory calibration, 23 °C ± 3 °C, at 95 % confidence level) at 50 MHz and 223.61 mV, using a serialized one meter cable, characterized at that point for RF power meter 0 dBm reference output measurement. In the RF power measurement mode, the accuracy is specified to the end of the serialized cable with a curve fit for the other ranges and frequencies that is a first order correction for cable loss. |