Measurement Computing

(508) 946-5100

3

info@mccdaq.com

mccdaq.com

USB-2001-TC

Specifications

Specifications

All specifications are subject to change without notice.

Typical for 25 °C unless otherwise specified.

Analog input

Number of channels: One

ADC resolution: 20 bits

Input ranges: ±73.125 mV, calibrated, ±146.25 mV, not calibrated. Used for open

thermocouple detection.

Common-mode range

Channel-to-USB ground: ±30 V

Common-mode rejection ratio (0 to 60 Hz)

Channel-to-USB ground: >145 dB

Noise rejection

50/60 Hz: >80 dB

Temperature measurement ranges: Proper function over the temperature ranges

defined by NIST (type J, K, R, S, T, N, E, and B). Type E maximum is 900 ºC.

Conversion time: 250 ms

Input bandwidth

–3 dB: 1 Hz

Differential input impedance: 20 MΩ between isolated 3.3 V and ground

Input noise: 2 µVpp

Open thermocouple bias voltage: 3.3 V

Cold-junction compensation sensor accuracy:

0 ºC to 65 ºC: 1.25 °C max, 0.6 °C typ

Cold-junction compensation sensor resolution: 0.0625 °C typ

Overvoltage protection: 30 V max between TC+ and TC–

Channel configurations

Thermocouple type:

J, K, S, R, B, E, T, or N; one differential channel.

Channel configuration information is stored in internal FLASH Program

Memory on the microcontroller by the firmware whenever any item is modi-

fied. Modification is performed by commands issued over USB from an external

application, and the configuration is non-volatile.

The factory default configuration is undefined ‘#’.

Compatible thermocouples

Thermocouple

J: –210 °C to 1200 °C

K: –270 °C to 1372 °C

R: –50 °C to 1768 °C

S: –50 °C to 1768 °C

T: –270 °C to 400 °C

N: –270 °C to 1300 °C

E: –270 °C to 900 °C

B: 0 °C to 1820 °C

Temperature accuracy

Refer to the USB-2001-TC User’s Guide for an accuracy error chart for each ther-

mocouple type.

LED indicator

LED status:

Steady green: The device is powered and ready for operation.

Blinking green: The device is powered, but not yet enumerated by the USB.

Off: The device is not powered or is in USB suspend.

Power

Current consumption from USB: 150 mA maximum, 100 mA typical

Suspend current: 2.5 mA maximum

Recommended warm-up time: 15 minutes

Safety voltages

Connect only voltages that are within these limits.

Isolation

Channel-to-earth ground

: +30 V maximum

Measurement Category I is for measurements performed on circuits not directly

connected to the electrical distribution system referred to as MAINS voltage.

MAINS is a hazardous live electrical supply system that powers equipment. This

category is for measurements of voltages from specially protected secondary

circuits. Such voltage measurements include signal levels, special equipment,

limited-energy parts of equipment, circuits powered by regulated low-voltage

sources, and electronics.

30 V

Isolation

Barrier

SPI

TC

input

Low pass

filter

20-bit

ADC

I/O

Isolator

USB connector

(PC)

Full-speed

USB 2.0

USB 2.0

Microcontroller

Temperature

sensor / CJC

LED

+

-

USB-2001-TC Block Diagram