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Model 218 specifications

Input specifications

	Sensor temperature coefficient	Input range	Excitation current	Display resolution	Measurement resolution	Electronic accuracy
Diode	negative	0 V to 2.5 V	10 µA ±0.05% ⁹	100 µV	20 µV	±200 µV ±0.01% of rdg
Diode	negative	0 V to 7.5 V	10 µA ±0.05%⁹	100 µV	20 µV	±350 µV ±0.02% of rdg
PTC RTD	positive	0 Ω to 250 Ω	1 mA ±0.3%¹⁰	10 mΩ	2 mΩ	±0.06 Ω ±0.02% of rdg
	positive	0 Ω to 500 Ω	1 mA ±0.3%¹⁰	10 mΩ	2 mΩ	±0.06 Ω ±0.02% of rdg
	positive	0 Ω to 5000 Ω	1 mA ±0.3%¹⁰	100 mΩ	20 mΩ	±0.4 Ω ±0.04% of rdg
NTC RTD	negative	0 Ω to 7500 Ω	10 µA ±0.05%⁹	100 mΩ	50 mΩ	±0.8 Ω ±0.04% of rdg

⁹ Current source error has negligible effect on measurement accuracy
¹⁰ Current source error is removed during calibration

Thermometry

Number of inputs	8
Input configuration	Inputs separated into two groups of four (each group must be the same sensor type) — inputs can be configured from the front panel to accept any of the supported input types
Input accuracy	Sensor dependent — refer to Input Specifications table
Measurement resolution	Sensor dependent — refer to Input Specifications table
Maximum update rate	16 rdg/s total
User curves	Room for 8 (1 per unit) 200-point CalCurves™ or user curves
SoftCal™	Improves accuracy of DT-470 diode to ±0.25 K from 30 K to 375 K; improves accuracy of platinum RTDs to ±0.25 K from 70 K to 325 K; stored as user curves
Math	Maximum, minimum, and linear equation (Mx + B) or M(x + B)
Filter	Averages 2 to 64 input readings

Sensor input configuration

	Diode/RTD
Measurement type	4-lead differential
Excitation	8 constant current sources
Supported sensors	Diodes: Silicon, GaAlAs RTDs: 100 Ω Platinum, 1000 Ω Platinum, Germanium, Carbon-Glass, Cernox®, and Rox™
Standard curves	DT-470, DT-500D, DT-670, CTI-C, PT-100, and PT-1000
Input connector	25-pin D-sub

Front panel

Display	4-line by 20-character backlit LCD display
Number of reading displays	1 to 8
Display units	K, ºC, V, and Ω
Reading source	Temperature, sensor units, max, min, and linear equation
Display update rate	All displayed inputs twice in 1 s
Temp display resolution	0.001º from 0º to 99.999º, 0.01º from 100º to 999.99º, 0.1º above 1000º
Sensor units display resolution	Sensor dependent to 5 digits
Display annunciators	Remote operation, alarm, data logging, max, min, and linear
Keypad	Membrane keypad, 20-key, numeric and specific functions
Front panel features	Front panel curve entry and keypad lock-out

Interface

IEEE-488.2 interface (218S)
Features	SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT0, C0, E1
Reading rate	To 16 rdg/s
Software support	LabVIEW™ driver
Serial interface
Electrical format	RS-232C
Max baud rate	9600 baud
Connector	9-pin D-sub
Reading rate	To 16 rdg/s (at 9600 baud)
Printer capability	Support for serial printer through serial interface port used with data log parameters
Alarms
Number	16: high and low for each input
Data source	Temperature, sensor units, and linear equation
Settings	Source, high setpoint, low setpoint, deadband, latching or non-latching, and audible on/off
Actuators	Display annunciator, beeper, and relays (218S)
Relays (218S)
Number	8
Contacts	Normally open (NO), normally closed (NC), and common (C)
Contact rating	30 VDC at 5 A
Operation	Each input may be configured to activate any or all of the eight relays — relays may be activated on high, low, or both alarms for any input, or manually
Connector	Detachable terminal block
Analog voltage output (218S)
Number	2
Scale	User selected
Update rate	To 16 rdg/s
Data source	Temperature, sensor units, and linear equation
Range	±10 V
Resolution	1.25 mV
Accuracy	±2.5 mV
Min load resistance	1 kΩ (short-circuit protected)
Data logging
Channels	1 to 8
Operation	Data log records can be stored in memory or sent to the printer; stored data may be displayed, printed, or retrieved by computer interface
Data memory	Maximum of 1500 single reading records, non-volatile

General

Ambient temperature	15 °C to 35 °C at rated accuracy, 10 ºC to 40 ºC at reduced accuracy
Power requirement	100, 120, 220, 240 VAC, (+6%, -10%), 50 or 60 Hz, 18 VA
Size	216 mm W × 89 mm H × 318 mm D (8.5 in × 3.5 in × 12.5 in), half rack
Weight	3 kg (6.6 lb)
Approval	CE mark, RoHS