Model 224 specifications

Input specifications

 Sensor temperature coefficient Input range Excitation current Display resolution Measurement resolution Electronic accuracy at 25 °C3Measurement temperature coefficient
NTC RTD Negative0 Ω to 10 Ω1 mA60.1 mΩ0.15 mΩ±0.002 Ω ±0.06% of rdg(0.01 mΩ + 0.001% of rdg/°C
0 Ω to 30 Ω300 µA60.1 mΩ0.45 mΩ±0.002 Ω ±0.06% of rdg(0.03 mΩ + 0.0015% of rdg/°C
0 Ω to 100 Ω100 µA61 mΩ
1.5 mΩ±0.01 Ω ±0.04% of rdg(0.1 mΩ + 0.001% of rdg/°C
0 Ω to 300 Ω30 µA61 mΩ
4.5 mΩ±0.01 Ω ±0.04% of rdg(0.3 mΩ + 0.0015% of rdg/°C
0 Ω to 1 kΩ10 µA610 mΩ
15 mΩ +0.002% of rdg±0.1 Ω ±0.04% of rdg(1 mΩ + 0.001% of rdg/°C
0 Ω to 3 kΩ3 µA610 mΩ
45 mΩ +0.002% of rdg±0.1 Ω ±0.04% of rdg±0.1 Ω ±0.04% of rdg (3 mΩ + 0.0015% of rdg/°C
0 Ω to 10 kΩ1 µA6100 mΩ150 mΩ +0.002% of rdg±1.0 Ω ±0.04% of rdg(10 mΩ + 0.001% of rdg/°C
0 Ω to 30 kΩ300 nA6100 mΩ450 mΩ +0.002% of rdg±2.0 Ω ±0.04% of rdg(30 mΩ + 0.001% of rdg/°C
0 Ω to 100 kΩ100 nA61 Ω1.5 Ω +0.005%
of rdg
±10.0 Ω ±0.04% of rdg(100 mΩ + 0.002% of rdg/°C
DiodeNegative0 V to 2.5 V 10 µA ±0.05%4,5 10 µV10 µV±80 µV ±0.005% of rdg10 µV + 0.0005% of rdg/°C
0 V to 10 V10 µA ±0.05%4,5 100 µV20 µV±320 µV ±0.01% of rdg20 µV + 0.0005% of rdg/°C
PTC RTD Positive0 Ω to 10 Ω1 mA60.1 mΩ0.2 mΩ±0.002 Ω ±0.01% of rdg0.01 mΩ + 0.001% of rdg/°C
0 Ω to 30 Ω1 mA60.1 mΩ0.2 mΩ±0.002 Ω ±0.01% of rdg0.03 mΩ + 0.001% of rdg/°C
0 Ω to 100 Ω1 mA61 mΩ2 mΩ±0.004 Ω ±0.01% of rdg0.1 mΩ + 0.001% of rdg/°C
0 Ω to 300 Ω1 mA61 mΩ2 mΩ±0.004 Ω ±0.01% of rdg0.3 mΩ + 0.001% of rdg/°C
0 Ω to 1 kΩ1 mA610 mΩ20 mΩ±0.04 Ω ±0.02% of rdg1 mΩ + 0.001% of rdg/°C
0 Ω to 3 kΩ1 mA610 mΩ20 mΩ±0.04 Ω ±0.02% of rdg3 mΩ + 0.001% of rdg/°C
0 Ω to 10 kΩ1 mA6100 mΩ200 mΩ±0.4 Ω ±0.02% of rdg10 mΩ + 0.001% of rdg/°C

3With current reversal enabled for RTD measurements
4 Current source error has negligible effect on measurement accuracy
5 Diode input excitation can be set to 1 mA
6 Current source error is removed during calibration

Sensor input configuration

Measurement type 4-lead differential
ExcitationConstant current with current reversal for RTDs
Supported sensors RTDs: Cernox®, 100 Ω platinum, 1000 Ω platinum, Germanium, Carbon-glass, and Rox™
Diodes: silicon, GaAlAs
Standard curves DT-470, DT-670, DT-500D, DT-500-E1, PT-100, PT-1000, RX-102A, and RX-202A
Input connector 6-pin DIN


Number of inputs 12 (2 dedicated; 10 scanned)

Input configuration Inputs can be configured independently from the front panel to accept any of the supported input types

Isolation Sensor inputs optically isolated from other circuits but not from each other

A/D resolution 24-bit

Input accuracy Sensor dependent, refer to Input Specifications table

Measurement resolution Sensor dependent, refer to Input Specifications table

Maximum update rate 10 rdg/s on each non-scanned input, 5 rdg/s when configured as 100 kΩ NTC RTD with reversal on; 2 rdg/s on each scanned input; update rate is dependent on the number of channels enabled (typically from 10 rdg/s for 1 channel to 2 rdg/s for all 10 scanned channels)

Autorange Automatically selects appropriate NTC RTD or PTC RTD range

User curves Room for 39 200-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 and minimum

Filter Averages 2 to 64 input readings

Front panel

Display 8-line by 40-character (240 × 64 pixel) LCD display module with LED backlight

Number of reading displays 1 to 12

Display units K, °C, V, mV, Ω

Reading source Temperature, sensor units, max, and min

Display update rate 2 rdg/s

Temperature display resolution 0.0001° from 0° to 99.9999°, 0.001° from 100° to 999.999°, 0.01° above 1000°

Sensor units display resolution Sensor dependent, to 6 digits

Other displays Input name

Display annunciators Alarm

LED annunciators Remote, Ethernet status, alarms A – D 

Keypad 23-key silicone elastomer keypad

Front panel features Front-panel curve entry, display contrast control, and keypad lockout



Capabilities SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT0, C0, E1

Reading rate To 10 rdg/s on each input

Software support LabVIEW™ driver


Function Emulates a standard RS-232 serial port

Baud rate 57,600

Connector B-type USB

Reading rate To 10 rdg/s on each input

Software support LabVIEW™ driver


Function TCP/IP, web interface with built-in utilities

Connector RJ-45

Reading rate To 10 rdg/s on each input

Software support LabVIEW™ driver


Number 12, high and low for each input

Data source Temperature or sensor units

Settings Source, high setpoint, low setpoint, deadband, latching or non-latching, audible on/off, and visible on/off

Actuators Display annunciator, beeper, and relays


Number 2

Contacts Normally open (NO), normally closed (NC), and common (C)

Contact rating 30 VDC at 3 A

Operation Activate relays on high, low, or both alarms for any input, or manual mode

Connector Detachable terminal block


Ambient temperature 15 °C to 35 °C at rated accuracy; 5 °C to 40 °C at reduced accuracy

Power requirement 100, 120, 220, 240 VAC, ±10%, 50 or 60 Hz, 35 VA

Size 435 mm W × 89 mm H × 368 mm D (17 in × 3.5 in × 14.5 in), full rack

Weight 7.6 kg (16.8 lb)

Approval CE mark, RoHS

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