8/16-channel smart sensor interface | Model 418/419
- Measures thermocouples, RTDs, strain gages, thermistors, 4-20 mA, voltage and resistance
- 8 high-accuracy differential input channels
- Integral sensor excitation
- Exclusive pulsed excitation minimizes sensor self-heating
- Configurable sensor type per channel
- Fully electronic calibration
Model 418/419 is obsolete. This archived information is provided as a courtesy to customers who own model 418/419 units.
Description
Sensoray models 418 and 419 offer an easy and cost-effective way to acquire sensor data for any ISA bus system. They feature 16-bit resolution from 8 or 16 channels, each individually programmable for different sensor types.
An on-board microcomputer continually scans the active sensor channels. Each channel is amplified, digitized, filtered, linearized, converted to engineering units, and stored in on-board memory, all independent of host CPU activity. Analog to digital conversion is performed in under 22 milliseconds, providing 45 channels per second scan rate.
A pulsed constant-voltage source is provided for strain and pressure sensors, and a pulsed constant-current source is provided for resistive sensors, thus minimizing sensor self-heating. Lead loss errors from RTD's, thermistors, and resistors are eliminated with the use of a four-wire circuit.
The boards plug directly into standard ISA bus slots. Sensor field wiring is accomplished with a 37-conductor flat cable and remotely mountable screw-termination board, either model 7409TB or model 7409TDIN with DIN rail mounting hardware.
Model 418 / 419 application
Calibration
Precision reference standards are periodically sampled and used to eliminate gain and offset errors from sensor measurements. Signal conditioning is provided for thermistors, RTD's, thermocouples, strain and pressure, resistance and voltage inputs.
Calibration data is stored in EEPROM so the adapter board may be easily interchanged. Calibration is fully electronic — physical trimpots have been eliminated, along with the need for board access during recalibration.
Specifications
| Input resistance | 100 MΩ |
| Maximum input voltage | 63 VAC rms |
| CMMR | 95 db/min |
| Maximum command mode | ±5 V |
| A/D converter | 16-bit integrating |
| Conversion time | 22 ms/channel |
| A/D scan rate | 45 samples/second |
| Operating temperature | -25 to 70 °C |
| PC/104 interface | 2 I/O ports |
| Input power | 5 V (at 100 mA)
12 V (at 45 mA) |
| Sensor Types | |
|---|---|
| Thermocouples | J, K, T, S, E, B, N, C, R |
| Platinum RTD | 100 Ω, types 385 and 392 |
| Nickel RTD | 120, 200, 1000 Ω |
| Copper | 10 Ω |
| Thermistors | 10000 Ω, YSI type 44006 or 44031 |
| Strain gauges | 120 to 4000 Ω |
| Sensor | Resolution | Range |
|---|---|---|
| Thermocouples | 0.1 °C | -270 to 1760 °C |
| Thermistors | 0.01 °C | -55 to 145 °C |
| Resistors | 0.02 Ω
0.125 Ω 31 Ω |
0 to 400 Ω
0 to 3 kΩ 0 to 600 kΩ |
| RTDs | 0.05 °C
0.0125 °C |
-200 to 800 °C
0 to 400 °C |
| Strain/pressure | 5 µV | ±100 mV |
| DC voltage | 5 µV
20 µV 200 µV |
±100 mV
±500 mV ±5 V |
Documentation
| File | Version | Date M-D-Y | Type | Size |
|---|---|---|---|---|
| Model 418/419 Instruction Manual | 1.0.0 | 10-17-24 | 167 KB |
Downloads
| File | Version | Date M-D-Y | Type | Size |
|---|---|---|---|---|
| Smart A/D Software Development Kit | 1.0.2 | 10-17-24 | ZIP | 243 KB |
| Other Operating Systems | ||||
| Need a software development kit for another operating system? We can port our SDK to your OS for a NRE fee or, with a volume commitment, at no additional cost. Contact Sales for details. | ||||