Model 268-RTD - 3 1/2 Digit RTD Meter

3 1/2 DIGIT RTD METER
MODEL 268-RTD

1/8 DIN (1A) Case

Connections Diagram

STANDARD FEATURES

100 ohm Platinum RTD input

Sensor excitation

1° or 0.1° resolution

Display in °C or °F

Bright, 0.56 in (14.2 mm) LED digits

120 dB CMR up to 500 V

Parallel BCD output Screw-terminal barrier strip

1/8 DIN case

OPTIONS

Buffered, isolated, gated and stored BCD

IEEE-488 (GPIB) interface

1 mV/count linearized analog output

HI or LO alarm setpoint

5 V dc, 9-32 V dc or 26-56 V dc power

Bench-style case with 1 or 12 inputs

Model 268-RTD is a low-cost, 3 1/2 digit RTD meter with a wide range of output options. It is available in four standard configurations for 100 platinum RTD's with alpha of 0.00385. Readout can be in °C or °F with 1° or 0.1° resolution. Non-isolated parallel BCD output is standard.

PANEL-MOUNT OR BENCH-STYLE CASE
The standard case of the 268-RTD is 1/8 DIN-sized and is suitable for panel mounting. It can also be mounted in an optional bench-style case. This case is available for one RTD input or with a rotary switch for 12 inputs.

OUTPUT OPTIONS
Upper-board output options of the 268-RTD include five different BCD output boards, an IEEE-488 (GPIB) communi-cations interface, a 1 mV/count analog output, and a single-setpoint controller with reed-relay output. For additional information, please refer to the Options and Mechanical sections.

SPECIFICATIONS

ANALOG INPUT
Sensor type: 100 ohm platinum RTD with alpha 0.00385
Calibration: To DIN 43760, September 1968
Overvoltage protection: 6 Vp
Current excitation, nominal: 0.1 mA (PC1 & PF1), 0.5 mA (PC2 & PF2)
Max lead resistance: 10 per conductor (add ±0.005% of reading/ to overall error)
Zero tempco (bridge-network error): ±0.02 deg/deg
Span tempco: ±0.006% of reading/°C

NOISE REJECTION
NMR: 60 dB, 50/60 Hz
CMR: 120 dB, DC to 60 Hz
CMV: `500 Vp.

ANALOG-TO-DIGITAL CONVERSION
Input configuration: Bridge
Technique: Dual-slope, average-value, ratiometric
Polarity: Automatic
Signal integration period: 100 ms
Read rate: 3 to 4/s

TEMPERATURE RANGE	CONFORMITY ERROR	ACCURACY ±1/2 count	Resoulution (degrees)	MODEL #
-210 to +100°C +100 to +800°C	±0.2°C ±0.2 R	±0.7°C ±0.25% R	1°C	268-PC1
-199.9 to +199.9°C	±0.2°C	±0.3°C	0.1°C	268-PC2
-330 to +212°F +212 to +1500°F	±0.3°F ±0.2% R	±0.8°F ±0.25% R	1°F	268-PF1
-199.9 to +199.9°F	±0.3°F	±0.4°F	0.1°F	268-PF2

DISPLAY
Type: 7-segment, red LED
Height: 0.56 in (14.2 mm)
Symbols: 188.8
Overrange indication: Display Flashes
Leading-zero blanking: Automatic

DIGITAL SIGNALS
Input signals: TTL and 5 V CMOS compatible
Output signals: TTL-compatible

POWER
AC voltages: 120/240 V ac, ±15%
AC frequency: 50/60 Hz
AC Power consumption: 4.5 W
DC voltages: 5 V dc ±5%, non-isolated,9-32 V dc, isolated to 300 Vp; 26-56 V dc, isolated to 300 Vp;
DC power consumption: 3.5 W at 5 V dc, 5.5 W at 9-32 V dc

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

MECHANICAL

Panel-Mount Case
Dimensions: Newport DIN1A (1/8 DIN case)
(see Mechanical section for drawings)
Weight: 19 oz (540 g)
Case material: 94V-0 UL-rated polycarbonate

Bench-Mount Case
Dimensions: 8.5 x 8.8 x 3.0 in (W x D x H) (21.6 x 22.1 x 7.6 cm)
Weight (including 268): 3.5 lbs (1.60 kg)
Case material: Metal enclosure