Model 204B - 3 3/4 Digit DC Voltmeter with BCD Output

3 3/4 DIGIT DC VOLTMETER WITH BCD OUTPUT
MODEL 204B - OPTION AVG/RMS

NEMA-SIZE Case

Connections Diagram

STANDARD FEATURES
Parallel BCD output
±3,999-count display span
±40 mV to ±400 V dc ranges
3-wire ratio input
1500 Vp CMV, 120 dB CMR
Bright, 0.56 in (14.2 mm) LED display
Automatic zero and polarity
115/230 V ac power
1/8 DIN case

OPTIONS
±4,999-count display span
±5,999-count display span
High-impedance 3-wire ratio input
Isolated, stored, three-state parallel BCD
IEEE-488 (GPIB) interface
Digital setpoint controller
Digital peak or valley hold
0.5 mV/count analog output
5 V dc power
Isolated 9-32 V dc power
Isolated 26-56 V dc power
Screw-terminal barrier strip
NEMA-4 splash-proof lens cover
NEMA-size case

In its base configuration, Model 204B is a high-accuracy ±3,999-count DC voltmeter which fills the gap between 3 1/2 and 4 1/2 digit resolution. The most sensitive standard input range is ±39.99 mV full-scale and provides 10 µV resolution. Extended-range options are available to ±4,999 and ±5,999 counts. Accuracy is 99.95% of reading.

BCD OUTPUT STANDARD
Unbuffered, non-isolated parallel BCD output is a standard feature of the 204B and is implemented on the main circuit board. It is good for about 1 feet and can be used to interface the 204B to a comparator (Model 872A) or a printer (Model 820A). Additional data and control outputs can be provided by an optional upper board.

OPTIONS

The 05 Option provides a DC signal proprtional to the display to drive an X-Y recorder or strip-chart recorder.

The meter main assembly can be electrically configured for five input ranges, four display spans, a dummy right-hand zero, high-impedance 3-wire ratio input, extended zero adjustment, and optical isolation between analog and digital grounds. Upper-board options include four BCD output boards, an IEEE-488 (GPIB) communications interface, linearized 0.5 mV/count analog output, and a single setpoint controller. Mechanical options for the standard 1/8 DIN case include a screw-terminal barrier strip for signal and power and a splash-proof lens cover which meets NEMA-4 requirements. A NEMA-size case is optional. For additional information, please refer to the Options and Mechanical sections.

SPECIFICATIONS

ANALOG INPUT

Signal Range	±39.99 mV	±399.9 mV
Resolution	10 µV	100 µV
Input resistance	1 Gohm	1 Gohm
Bias current	1 nA	1 nA
Maximum input	100 Vp	100 Vp

Signal Range	±3.999 mV	±39.99 mV	±399.9 mV
Resolution	1 mV	10 mV	100 mV
Input resistance	1 Gohm	1.1 Mohm	1.0 Mohm
Bias current	1 nA	100 pA	10 pA
Maximum input	100 Vp	250 Vp	500 Vp

NOISE REJECTION
NMR: 40 dB, 50/60 Hz
CMR: 120 dB, DC to 60 Hz
CMV: 1500 Vp per HV test, 354 Vp per IEC spacing

ACCURACY AT 25°C
Maximum error: ±0.02% of reading ±1 count
Span tempco, 4V range: ±0.005% of reading/°C
Span tempco, other ranges: ±0.01% of reading ±1 count
Step response: 1 s
Warmup to rated accuracy: 1 hour

ANALOG-TO-DIGITAL CONVERSION
Technique: Dual-slope, average value
Polarity: Automatic
Signal integration period: 50 ms at 60 Hz, 40 ms at 50 Hz
Read rate: 3.6/s at full scale

3-WIRE RATIO REFERENCE

Input range	±40 mV	±400 mV	±4, ±40, ±400 V
Reference Voltage	+0.01 to +0.08V	+0.1 to +0.8 V	+1.0 to +3.5 V
Load on reference, std	47 ohm	471 ohm	4.72 kohm
Load on reference, opt	100 Mohm	100 Mohm	100 Mohm
Accuracy w/100 Mohm	99.8% ±0.2%	99.8% ±0.2%	99.8% ±0.2%

DISPLAY
Type: 7-segment, red LED
Height: 0.56 in (14.2 mm)
Symbols: 8.8.8.8
Decimal points: Three positions internally or at connector
Overrange indication: Display flashes

DIGITAL INPUTS
Output signals: TTL-compatible
HOLD input: TTL or 5 V CMOS compatible
BLANKING input: Open-collector compatible

POWER
AC voltages: 115 V ac ±10% at 60 Hz; 230 V ac ±10% at 50 Hz
DC voltages: 5 V dc ±5%, non-isolated; 9-32 V dc, isolated to 300 Vp; 26-56 V dc, isolated to 300 Vp
Power consumption: 5 W nominal

ENVIRONMENTAL
Operating temperature: 0 to 50°C
Storage temperature: 40 to +75°C
Relative humidity: 95% at 40°C (non-condensing)

MECHANICAL
Dimensions: Newport DIN1A (1/8 DIN) case standard, Newport NEMA-size case optional (see Mechanical section for drawings)
Weight: 17 oz (480 g)
Case material: 94V-0 UL-rated polycarbonate