Wattmeter - Model 2335
  Dc to more than 1MHz
Inputs
up to 10A and 1000V
0.2%
Uncertainty
Low
Power Factor Accuracy
Peak or
RMS Readings
Isolated Inputs
Harmonic Analysis
Multifunction Displays
IEEE-488.2 and RS-232
TRUE RMS/REALLY BROADBAND
The Model 2335 Sampling Watmeter is a precision, high accuracy, auto-ranging
instrument which simultaneously measures and displays true rms Voltage, true rms Current
and true mean Power over a frequency range from dc to more than 1MHz. Full scale Current
and Voltage inputs are typically measured within ±0.1% of the
reading in amplitude to at least 500kHz. The corresponding Power is typically measured to
within ±0.1% of the input Volt-Amperes to 250kHz and to
within ±0.2% of the input Volt-Amperes to 500kHz for loads
having any Power Factor.
LOW POWER FACTOR ACCURACY.
Five digits or resolution combined with excellent phase matching between the current and
voltage channels make the Model 2335 Wattmeter an exceptionally good instrument for making
low power factor measurements up to 1MHz. This makes the instrument ideal for high
frequency core loss measurements which are inherently low power factor.
MULTI-FUNCTION
In addition to the rms Voltage, rms Current, and mean square Power the Model 2335
Wattmeter also measures simultaneously the peak Voltage, the peak Current and the
Frequency and calculates the Volt-Ampere product, the Power Factor and the Harmonics of
the current and the voltage. These functions may be displayed or may be read over the
IEEE-488.2 or RS-232 interfaces.
UNPARALLELED HIGH FREQUENCY ACCURACY
The Model 2335 Wattmeter allows broadband and high accuracy measurements of both
sinusoidal and highly distorted wave shapes. The Current, Voltage, Power, and Power Factor
accuracies to 1MHz of the Model 2335 Wattmeter far exceed any other sampling wattmeter, or
for that matter, with respect to Current or Voltage, almost all conventional multimeters.
Full scale Power ranges exist for loads with impedances from (0.6V/1.5A) = 0.4W to (600V/1.5mA) = 400kW.
WIDE MEASUREMENT RANGE
The Model 2335 Wattmeter has full scale Power ranges from 1.0000mWatt to 10000Watts. With
external shunts or current to voltage transducers the upper range may be extended by a
factor of ten or one hundred. Full scale Voltage from 2.000V to 2000V (usable to 1000V)
and full scale Current ranges from 5.000mA to 5.000A (all rms values) cover a wide range
of load impedances. Full scale Current and Voltage inputs may have crest factors up to
three while smaller inputs may have even higher crest factors. Sinusoidal inputs with rms
values of twice the nominal Full Scale value may be measured with no loss in accuracy.
POSSIBLE MEASUREMENT USES
Measurement of Ultrasonic Equipment of all types and power levels, Finished Transformers,
Transformer Core Material, Switching Power Supplies, Fluorescent Lamp Ballasts of all
types, Mercury Arc Lamp Circuits, Sodium Lamp Ballasts, Speed Controlled Motors of all
types, Efficiency of any device with an electrical input and an electrical output, SCR
Controlled Devices of all types, High Frequency and/or Distorted Currents from any source,
Voltage Response of any device from DC to 1MHz, and the Characteristics of Electric
Automobile Drives.
EASY TO CALIBRATE AND MAINTAIN
The Model 2335 Wattmeter is an all solid state instrument with optically isolated input
channels. DC coupling in both channels allows calibration and/or verification with
high accuracy dc sources. Internal software calibration routines allow most recalibrations
to be accomplished without opening the instrument and without screwdriver
adjustments.
UNIQUE SAMPLING APPROACH / ISOLATED INPUTS
The Voltage and Current inputs of the Model 2335 Wattmeter are simultaneously sampled
(with 16 bit resolution), converted to digital form, and transmitted via optical links to
the main chassis. This allows both the Current and Voltage inputs to be completely
isolated from each other and from the main chassis. The asynchronous sampling frequency is
controlled by the system microprocessor in such a fashion that neither it nor any of its
harmonics can come close to the measured input frequency or any of its harmonics. This
precaution prevents "beats" with their accompanying jitter in the displayed
values.
REMOTE CONTROL
The Model 2335 Wattmeter is equipped with an IEEE-488.2 interface and an RS-232 interface
which both incorporate all of the IEEE-488.2 Common Commands and Queries. Any function
that can be entered via the front panel can be controlled via either interface. In
addition, any or all of the functions which can be displayed, can be queried and sent
simultaneously to the Controller over the either interface. The status (e.g. Current
range, Voltage range, etc) of the instrument may also be queried and sent over either
interface..
The bus address for the IEEE-488 interface is set from the front panel and is displayed
both at turn-on and when the Local key is depressed. A Remote lamp indicates that the
Model 2335 Wattmeter has been placed in its Remote state by the IEEE-488 Controller.
SPECIFICATIONS
Range, Resolution and Input Impedance (Voltage
Channel)
| Full Scale Voltage |
Max. Peak Value |
Resolution |
Input Impedance |
| 2.000V |
6V |
1mV |
1.05M/15pF |
| 20.00V |
60V |
10mV |
1.01M/15pF |
| 200.0V |
600V |
100mV |
1.00M/15pF |
| 2000 V |
3000V |
1 V |
1.00M/15pF |
| The 2000V range is useable to
1000V rms |
Range, Resolution and Input Impedance (Current Channel)
| Full Scale Voltage |
Max. Peak Value |
Resolution |
Input Impedance |
| 5.000mA |
15mA |
1uA |
20 |
| 50.00mA |
150mA |
10uA |
2.1 |
| 500.0mA |
1500mA |
100uA |
0.27 |
| 5000 mA |
15A |
1mA |
0.039 |
| EXTernal (100mV) |
300mV |
- |
20 |
The Display on the EXT range is factory
settable to read any value up to 5000, with any positioning of the decimal point, for a
100mV input.
|
Uncertainty (rms) For the peak uncertainty,
multiple the table values by 2
| |
0% - 100% of Full Scale |
100% - 200% of Full Scale |
| Frequency |
±(% of Reading+% of Range) |
% of Reading |
| dc |
±(0.10 + 0.10) |
±0.20 |
| 5Hz - 250kHz |
±(0.10 + 0.10) |
±0.20 |
| 250kHz - 500kHz |
±(0.20 + 0.20) |
±0.40 |
| 500kHz - 1.0MHz |
±(0.40 + 0.40) |
±0.80 |
Isolation A ±1000Vdc may be placed between the LO
Voltage Terminal and Chassis
POWER AND POWER x 10
Ranges Eight decade Full Scale ranges from 1.0000mWatt to 10,000Watt. The ranges
are all combinations of a Full Scale Current range multiplied by a Full Scale Voltage
range plus a corresponding set of combinations with ten times the sensitivity which occur
when the Px10 range is activated.)
Resolution 1 part in 10000 of the Full Scale range
Uncertainty
| |
0% - 100% of Full Scale |
100% - 200% of Full Scale |
| Frequency |
±(% of V-A+% of Range) |
% of V-A |
| dc |
±(0.20 + 0.10) |
±0.30 |
| 5Hz - 250kHz |
±(0.20 + 0.10) |
±0.30 |
| 250kHz - 500kHz |
±(0.40 + 0.20) |
±0.60 |
| 500kHz - 1.0MHz |
±(0.80 + 0.40) |
±1.20 |
| (for any Power Factor) (V-A is the
Volt-Ampere product) |
Power x 10 Any Px10 range may be selected when both the Peak Current
and the Peak Voltage are less than 0.316 of their Peak Range values.
VOLT-AMPERES
Calculated as the product of the rms Current and the rms Voltage. It has the same
Full Scale ranges, resolution and uncertainty as POWER.
POWER FACTOR
Calculated as the ratio of Power to Volt-Amperes. It has a range from 0 to ±1.0000
and a resolution of .0001 for Volt-Ampere products greater than 7.5% of Full Scale.
The resolution decreases as the Volt-Ampere product decreases. The uncertainty is
±0.002 ±10 digits up to 250kHz, ±0.004 ±20 digits from 250kHz to 500kHz, and ±0.008
±40 digits from 500kHz to 1000kHz
HARMONICS
The Harmonics are specified for Fundamental values between 20Hz and 20kHz and for periodic
waveforms with rise times greater than 0.5% of the period. The resolution of the
Fundamental and Harmonics of the voltage and the current is identical to the specified
values for the corresponding rms voltage and current. The uncertainty of the Fundamental
value is also the same as the rms value. The total Harmonic uncertainty is the same
percentage as the total Fundamental uncertainty. For Fundamental values greater than
20kHz, the harmonic values are still calculated but the uncertainty may increase because
of some jitter in the readings.
FREQUENCY
Frequency of Voltage or Current from 5.0000Hz to greater than 2MHz with five digits of
resolution and an uncertainty of ±100ppm ±1 digit.
DISPLAYS
Three LED (10.9mm/.43 inch high) Displays. Two four digit displays for Current
and Voltage and a six digit display for Power and the other functions.
IEEE-488.2 INTERFACE SUBSETS: SH1, AH1, T6, L4, SR1, RL1, PP0,
DT0, DC1
RS-232 CHARACTERISTICS: 9600 Baud, 1 start bit, 8 data bits and 2 stop
bits.
| DISPLAY UPDATE |
10 times a second |
| |
|
| SETTLING TIME |
5 seconds to reach 0.1% of Full Scale |
TEMPERATURE RANGE
|
Operating |
0°C to 40°C |
|
Within Specifications |
18°C to 25°C |
|
Storage |
-40°C to
75°C |
|
Derate specifications by a factor of 2 when
operating outside the 18°C to 25°C temperature bracket. |
| |
|
| RELATIVE HUMIDITY |
Less than 90% |
| |
|
| WARM-UP TIME |
Thirty minutes for all specifications |
POWER REQUIREMENTS
|
100V ±10%, 120V ±10%, 220V ±10%, 240V ±10% (Rear Panel switch
selectable) 50Hz to 400Hz. 1/2A AGC Fuse for 120V operation.
Power Consumption less than 24Watt (60Hz-120V). |
PHYSICAL
|
Rack Mount kit available as an option |
|
Weight: |
6.85kilograms (15pounds) |
|
Size: |
43.2cm x 13.3cm x 33.0cm (17" x 5.25" x 13") |
|
