Temperature_Bridge_Specification.pdf

NDBC SPECIFICATION

FOR PROCUREMENT OF

REFERENCE TEMPERATURE BRIDGE

1.0 SCOPE

The NDBC is looking to purchase a second Reference Temperature Bridge to use in the calibration of NDBC operational air and ocean temperature sensors. This will allow NDBC to calibrate our temperature sensors year-round without a lapse due to bridge calibration or repairs. The Reference Temperature Bridge is intended to interface the NDBC’s current inventory of models 5699 and 5698 Platinum Resistance Thermometers (PRTs). A temperature bridge that includes microprocessor-based data collection, automatically calculates ITS-90 constants, and displays readout in temperature instead of resistance would reduce the required training time in the proper setup and use of the reference bridge. The intent is for NDBC to purchase one Reference Temperature Bridge cell capable of monitoring 6 PRTs simultaneously (or near simultaneously). Ideally the Reference Temperature Bridge would include a built-in ratio self-calibration function to simplify the use of the unit.

2.0 REQUIREMENTS

2.1 GENERAL

The procured item(s) shall include all hardware, software, and manuals necessary to operate and maintain the temperature bridge through both manual and externally programmable interfaces. NDBC will consider any system that meets or exceeds the specifications listed below.

2.2 TEMPERATURE BRIDGE SPECIFICATIONS

Resistance Range 0 Ω to 500 kΩ Resistance Ratio Accuracy @ Ratio

0.25 to 0.5 and 2.0 to 4.0 for 1 year

0.8 ppm or better

Resolution @ 100 Ω 0.5 ppm or better Minimum Measurement Period 2 seconds Data Collection Automated data collection via manual and external control Internal Data Logging ~25,000 individual time and date stamped readings with channel identifier Data Display Modes Temperature in °C (ITS-90)

Resistance in Ω Statistics Average, Mean, Max, Min, and

Difference SPRT Probe Connections 4-wire Banana plug, spade, & bare wire Internal Reference Resistors 1 Ω, 10 Ω, 100 Ω, 10 kΩ min

Current Source 0.001 mA to 15 mA External Communication RS-232 and/or USB Channels (# Probes) 6 minimum (may be achieved through use of a multiplexer with automatic switching).

Power 115 VAC (±10%), 60 Hz Calibration Must come with a 1 year NVLAP accredited or NIST traceable calibration report.

Warranty Period 1 Year min.

3.0 QUALITY ASSURANCE AND DELIVERABLES

NDBC has the right to verify operation of all units prior to final acceptance.

Deliverables shall include all hardware, software, cables and manuals necessary to operate and maintain the temperature bridge through both manual and externally programmable interfaces. A set of manuals must be provided with each unit purchased. Manuals may be electronic or hardcopy.

4.0 ORDERING DATA

Contract documents should specify the following:

Title, number and date of this specification or ordering contract Number and type of units to be delivered Requested delivery date and price Any additions to or deviations from this specification Destination freight delivery point:

National Data Buoy Center Attn: Property Officer Building 3202 Stennis Space Center, MS 39529