Attachment I - Specification Document- Barometer.pdf

Attachment 1

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ASOS BAROMETER SPECIFICATION

1. ASOS Barometer Requirements

1.1. General Requirements

The configuration of the ASOS Barometer shall be employed as a single unit of three barometers for redundancy and accuracy.

[BP-1] The three transducer, digital barometer must be a commercial off-the-shelf (COTS) or non-developmental item (NDI) sensor with an IP65 rating for outdoor installation in NEMA rated cabinets.

[BP-2] The barometer must be capable of providing barometer measurements in accordance with Section

1.2 and come delivered with a NIST traceable factory calibration certificate.

[BP-3] The barometer must be provided with a technical operating manual in an editable electronic format with permission for the Government to use for training/maintenance purposes.

[BP-4] The barometer must be capable of being mounted in any orientation on any axis.

[BP-5] The barometer must be capable of mounting in a standard 19” rack mount, 3U, or vertical mount on DIN Rail.

1.2. Required Self-Testing/Diagnostic Capability

The maintenance philosophy of the ASOS is to maximize the ability of today’s “smart” sensors to perform on-board diagnostics capable of detecting and reporting internal anomalies and/or failures, which adversely affect reporting accuracy. The Government’s goal will be to procure a barometer capable of identifying and fault-isolating all sensor-specific hardware and firmware anomalies.

[BP-6] The Vendor must identify the extent to which their barometer can provide these capabilities.

[BP-7] The Vendor must provide an interface document which details all communication and message formats relevant to this capability.

[BP-8] The barometer must provide off-line extended diagnostic procedures and tools must be provided for faults that cannot be detected by the self-testing/diagnostic capability.

Note: The off-line extended diagnostics are diagnostic procedures designed to be performed through external commands received via a maintenance technician laptop computer connected to the serial interface of the gauge. These diagnostic procedures may make use of extensive dialogue with the maintenance technician, and may use commonly available external test equipment and/or common hand tools if required.

1.3. Required Minimum Performance

1.3.1. Range

[BP-9] The barometer must measure pressures between 16.9 inches of mercury and 31.5 inHg, inclusive.

The barometer and the pressure sensor must be able to withstand pressures as low as 15.7 inHg and continue to operate after the exposure.

Note: The barometer and the sensor operational requirements must and will be waived at pressures lower than 16.9 inHg, i.e., the sensor does not have to measure pressures below 16.9 inHg.

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1.3.2. Resolution

[BP-10] The barometer must have a resolution of ≤0.003 inches of mercury (0.1hPa) or better.

1.3.3. Accuracy

[BP-11] The barometer sensor must be linear over the entire measurement range, with a minimum accuracy of + 0.02 inches of mercury full scale (worst case, including temperature change, hysteresis, and 3-month drift) over a 4.5 inHg measurement range at any altitude between -300 to 12,200 feet mean sea level.

1.3.4. Differential Accuracy

[BP-12] The barometer sensor shall exhibit a differential accuracy of 0.01 inch of mercury or less between any two pressure measurements taken from the same sensor 3 hours apart. (Ambient temperature over this 3-hour period shall not change more than 5 degrees F, ambient pressure shall not vary more than 0.1 inHg over the 3-hour period.)

1.3.5. Pressure Sensor Venting

[BP-13] The barometer must be equipped with a pressure-venting port & fitting.

1.3.6. Interrogation Rate

[BP-14] The barometer must be interrogable.

[BP-14a] The barometer must be updated and its measurements at a minimum of once every 10 seconds.

1.3.7 Mounting Hardware and Power Supply Solution

[BP-15] The barometric pressure sensor must include an installation kit containing ALL necessary power cables, data cables, hardware, and other ancillary items necessary for proper installation and operation.

[BP-15a] The barometer must be provided with power and data cables that are at least two (2) meters in length.

1.4 Barometer Solution Preferred Requirements

1.4.1. Environmental Durability

[BP-16] The barometer must be capable of maintaining operation and data communications within an environmental temperature range of -40 °F to +120 °F (-40.0 °C to 48.9 °C) for at least 48 hours..

[BP-17] The barometer must be capable of maintaining operation and data communications within an environmental relative humidity of 74% at 95 °F (35 °C) for at least 48 hours.

[BP-18] The barometer must be capable of returning to normal operation following environmental temperatures between -70 °F to -60 °F (-56.7 °C to -51.1 °C) for at least 48 hours.

[BP-19] The barometer must be capable of returning to normal operation after experiencing environmental temperatures between 120°F to 140°F (48.9 °C to 60 °C) for at least 48 hours.

[BP-20] The barometer must be capable of returning to normal operation after experiencing environmental relative humidity between 74% at 95 °F (35 °C) and 45% at 110.0 °F (43.3 °C) for 48 hours.

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1.4.2. Communication

[BP-21] The barometer sensor must be capable of interfacing with the CSI, CR1000X Data logger.

[BP-21a] The barometer must have a built-in asynchronous data interface mode capable of SDI-12, RS- 232 or RS 485 interface standards.

[BP-21b] The barometer must have user-selectable communication parameters (e.g., baud rate, parity, data bits, and stop bits).

1.5. Documentation

[BP-22] The barometer must be provided with documentation detailing storage, preparation, installation, operation, calibration, maintenance and repair instructions (as applicable).

[BP-23] The barometer must be provided with an Illustrated Parts List (IPL) of all interior and exterior barometer components and hardware.

[BP-24] Any software supplied with the barometer must provide detailed installation, preparation, maintenance, repair, and operation instructions.

1.6. Maintenance & Warranty

[BP-25] Each individual barometer shall possess a 1-year warranty minimum by the vendor for service, parts, and materials starting from the date of receipt and acceptance by the Government representative.

[BP-26] The vendor shall provide life cycle replacement parts for a minimum of 10 years.

[BP-27] The vendor shall be able to deliver replacement parts within 30 days of request or purchase.

1.7. Acceptance & Supply

[BP-28] Vendor shall be able to supply a quantity of 1000 calibrated barometer units of identical model and design, upon approval and acceptance.

[BP-29] Shipping costs for the units to the National Weather Service shall be included by the vendor in the price of each unit.

2. QUALITY ASSURANCE PROVISIONS

The barometer sensor must comply with this specification when installed in all environments defined in this specification. The Government will verify compliance with the requirements of this specification in general, and the following sub-paragraphs, using various testing methods. These methods will include field tests wherein the barometer sensor is exposed to outdoor environments and compared to a NWS standard, as well as possible rigorous laboratory testing wherein the barometer sensor will undergo exposure to an artificial environment specifically designed to demonstrate barometer sensor performance.

The contractor must demonstrate, through a formal test and inspection program or from actual field use statistics that the barometer sensor and its components meet the functional, environmental, reliability, maintainability, and availability requirements specified herein to the greatest extent possible.