Thermocouple / Millivolt Modules
Thermocouple / Millivolt Module
Two Millivolt modules enable the XR440 or XR450 Data Logger to read a millivolt signal on channel 3. One module, the Mvt-50u accepts a thermocouple (Type J, K, N, R, S, T, B, C, or E). A built-in precision thermistor on channel 1 provides ambient temperature readings and thermocouple cold junction compensation. An Mvt module configures the XR450 as follows: Ambient temperature on channel 1. Millivolt (or thermocouple if Mvt-50u) signal on channel 3. Channels 2 and 4 are 'Standard' channels and will accept Pace sensors, 0-5 Vdc or resistive signals.
Mvt Modules - Common Specifications
| Operating Temperature | -40°C to 60°C (-40°F to 140°F) |
| Size | 1.61" wide x 0.75" deep x 0.55" high (41mm x 19mm x 14mm) |
| Overall Size with XR450 Data Logger | Adds 0.35" (9mm) to XR450's overall length, no change to XR450's height and width |
| Thermistor Sensor | ±0.1°C interchangeability, 0-70°C |
| Input Type | Single ended, (-) terminal is internally connected to dc ground |
| Input Impedance | Greater than 10 M ohm |
Note: The last letter of the model number ('u' or 'b') signifies unipolar or bipolar input.
Electrical Specifications
| Model | Mvt-50u | Mvt-500u |
| Range | 0-50 mV | 0-500 mV |
| Resolution ( 12 bit ) |
12 uV | 120 uV |
| Offset Voltage | 5 uV max. | 5 uV max. |
| Offset Voltage Drift | 0.05 uV/ °C max. | 0.05 uV/ °C max. |
| Accepts Thermocouple | Yes | No |
| System Accuracy | 0.4% of F.S. | 0.4% of F.S. |
Part Numbers: (2 models) Mvt-50u, Mvt-500u
Price: (either model) $140.
Thermocouple Specifications for Mvt-50u
Mvt-50u Thermocouple Limitation
The Mvt-50u must be set (in Pocket Logger Software) to read either high or low temperatures. When set for high temperatures, the low temperature limit is the ambient temperature of the Mvt Module. When set for low temperatures, the high temperature limit is the ambient temperature of the Mvt Module.
Mvt-50u Thermocouple Specifications
| Type | Min Temp | Max Temp | Approx. Resolution |
| J | Ambient* | 760°C (1400°F) | 0.2°C (0.4°F) |
| K | Ambient* | 1220°C (2228°F) | 0.3°C (0.5°F) |
| N | Ambient* | 1300°C (2372°F) | 0.3°C (0.5°F) |
| R | Ambient* | 1760°C (3200°F) | 0.8°C (1.4°F) |
| S | Ambient* | 1760°C (3200°F) | 1.0°C (1.8°F) |
| T | Ambient* | 350°C (662°F) | 0.2°C (0.4°F) |
| B | Ambient* | 1820°C (3308°F) | 1.0°C (1.8°F) |
| C | Ambient* | 2320°C (4208°F) | 0.6°C (1.1°F) |
| E | Ambient* | 660°C (1220°F) | 0.15°C (0.3°F) |
| J 'low' | -130°C (-202°F) | Ambient* | 0.2°C (0.4°F) |
| K 'low' | -250°C (-418°F) | Ambient* | 0.3°C (0.5°F) |
| N 'low' | -50°C (-58°F) | Ambient* | 0.3°C (0.5°F) |
| T 'low' | -200°C (-328°F) | Ambient* | 0.2°C (0.4°F) |
| E 'low' | -100°C (-148°F) | Ambient* | 0.15°C (0.3°F) |
*Ambient temperature of Mvt-50u
