NWS Portable Barometer Standard Specifications_V8 Final (1) (1).docx.pdf

Appendix A

STERLING FIELD SUPPORT CENTER BAROMETER CALIBRATION LABORATORY

BAROMETRIC PRESSURE SPECIFICATIONS

1. Portable Field Reference Barometric Pressure Standard (PBPS) Requirements for ASOS and Upper Air Programs

1.1. General Requirements

[PBPS-1] The barometer shall be calibrated prior to delivery to the government and a calibration certificate will be provided with each individual unit.

[PBPS-2] The barometer shall be capable of displaying, remotely polling, and producing pressure readings in both inches of mercury (inHg) and hectopascals (hPa).

[PBPS-3] The barometer shall have no sharp edges, corners, nor protrusions that could cause personal injury.

[PBPS-4] The barometer shall include a front-facing, always-on digital display when operating through battery and AC electrical power.

[PBPS-5] The barometer display is preferred to comply with 2009 ICC A117.1 Digital Codes Chapter 7 Section 703.7 guidelines for Low Resolution Variable Message Signs.

[PBPS-6] The entirety of the barometer shall fit within a 22”W x 17”D x 11”H volume constraint during operation and shipment.

[PBPS-7] The barometer shall weigh less than or equal to 15lbs (6.8 kg).

[PBPS-8] The barometer may optionally be capable of being mounted inside an industry standard 19-inch electronics enclosure. The barometer will come with all the brackets, fasteners and face panel need to mount the instrument inside a 5U tall 19-inch rack (19.00 inch x 8.75 inch nominal panel size)

[PBPS-9] The barometer must have an external pressure test port adaptable to a 4AN compression fitting as per SAE Aerospace Standard AS4841.

[PBPS-10] The interior of the barometer shall be fully encapsulated by the exterior shell save for the external pressure port.

[PBPS-11] All barometers of a specific model delivered under the contract shall be identical in all respects, including pressure sensors, transmitters, associated circuitry and processing algorithms, physical characteristics and accessories, if any.

1.2. Portability

[PBPS-12] Must be self-contained, in rugged, dust and weather-proof/resistant enclosure for transport as part of an Electronics Technician’s equipment for the servicing of pressure sensors in the field.

[PBPS-13] All barometer casing, materials, parts, sensors, configurations, and calibrations shall be rigid and strong enough to withstand normal handling and shipping conditions via a common carrier including transportation shock and vibration within a foam padded enclosed water-resistant container. Units must be fully operational, including calibration and configurations, post-experiencing these transportation conditions. The vibration and shock requirements that each unit must withstand are listed below:

Vibration Requirements:

● Frequency Range: 3-5 HZ

● Displacement: 1in double amplitude

● Acceleration: Maximum 1.0 ± 0.1 g

Shock Requirements:

Gross Weight of Barometer and shipping Case Not Exceeding (lbs)

Dimensions of any Edge, height or diameter not exceeding (inches)

Free-Fall height of drop on all corners, edges, and flat faces (inches)

50 36 22

100 48 16

1.3. Interoperability

[PBPS-14] Must be capable of sustaining configuration settings while non-powered for a minimum of one year.

1.4. Performance Requirements

1.4.1. Measurement

[PBPS-15] The barometer shall be able to process and transmit pressure readings at a continuous rate of

10.0 seconds or faster via remote communications.

[PBPS-16] The barometer shall be able to process and display pressure readings at a continuous rate of

10.0 seconds or faster via its front-facing digital display.

[PBPS-17] The barometer shall be able to transmit continuous pressure readings via remote communications while simultaneously updating the front-facing digital display.

[PBPS-18] While continuously transmitting pressure readings via remote communications, the barometer shall have no more than 3% data loss over the duration of one hour.

1.4.2. Range

[PBPS-19] The barometer must be capable of measuring pressure between be 32.48 inches of mercury (1100 hPa) and 15.7 inches of mercury (531.66 hPa).

1.4.3. Resolution

[PBPS-20] Must have a resolution of ≤0.0003 inches of mercury (0.01hPa) or better.

1.4.4. Accuracy

[PBPS-21] Provide pressure with an accuracy of ±0.0074 inches of mercury (±0.25 hPa) or better across the full scale range of the device.

1.5. Environmental Durability

[PBPS-22] Capable of maintaining full operations and data communications over the environmental temperature range of -40 °F (-60 °F Preferred) to +120 °F (-40 °C to 48.9 °C) indefinitely when connected to an AC power source.

At low temperatures between -40 °F to +40 °F (-40 °C to +4.4 °C) the sensor shall be capable of maintaining operation for a minimum of 48 hours when using its internal battery power.

At middle temperatures between +40 °F to +95 °F (-4.4 °C to +35 °C) the sensor shall be capable of maintaining operation for a minimum of 200 hours when using its internal battery power.

At high temperatures between 95 °F to 120 °F (35 °C to 48.9 °C) the sensor shall be capable of maintaining operation for a minimum of 48 hours when using its internal battery power

[PBPS-23] Capable of maintaining operation and data communications within an environmental relative humidity range of 74% at 95 °F (35 °C) to 100% at 80°F (26.67°C) indefinitely when connected to an AC power source and for a minimum of 200 hours when using internal battery power.

[PBPS-24] Capable of returning to normal operation following exposure to extremely low temperatures between -70 °F to -40 °F (-56.7 °C to -40°C).

[PBPS-25] Capable of returning to normal operation following exposure to extremely high temperatures between 120°F to 140°F (48.9 °C to 60 °C).

[PBPS-26] Capable of returning to normal operation after experiencing extremely high dew points in the humidity range between 45% at 100.0 °F (43.3 °C) and 100% at 84°F (28.89 °C)

1.6. Communication

[PBPS-27] The barometer shall be able to interface remotely via a 9-pin RS232 serial cable or a provided USB cable.

[PBPS-28] The barometer shall be able to interface remotely via a baud rate between 9600 and 115200 baud.

[PBPS-29] The barometer shall be able to be polled, or continuously transmit, pressure data via remote commands alone.

[PBPS-30] The barometer shall be able to have its calibration coefficients read, adjusted, and saved via remote commands alone.

[PBPS-31] The barometer shall be able to have its calibration coefficients adjusted and saved without need of disassembling or exposing internal components to do so.

1.7. Documentation

[PBPS-32] Documentation shall provide storage, preparation, operation, calibration, maintenance and repair instructions.

[PBPS-33] Vendor shall provide an Illustrated Parts List (IPL) of all interior and exterior barometer components and hardware.

[PBPS-34] Any barometer related software shall provide installation, preparation, maintenance, repair, and operation instructions.

1.8. Power

[PBPS-35] Must have an internal battery capable of maintaining operation and data communications.

[PBPS-36] Must charge using a power supply that operates with an input of 115 VAC ± 10%, 60 Hz. The power supply cable must be compatible with a NEMA 1-15 Type A or NEMA 5-15 Type B connector.

1.9. Maintenance & Warranty

[PBPS-37] 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.

[PBPS-38] Each individual barometer shall have a life expectancy of 10 years, minimum.

[PBPS-39] The vendor shall provide an average life cycle for replacement parts, if available.

[PBPS-40] The barometer shall have maintenance costs minimized.

[PBPS-41] The vendor shall be able to deliver replacement parts within 30 days of request or purchase.

1.10. Acceptance & Supply

[PBPS-42] Vendor shall be able to supply 275 calibrated barometer units of identical model and design, upon approval and acceptance. (467 units if including Upper Air Program)

[PBPS-43] Shipping costs for the units to 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 may verify compliance with the requirements of this specification in general, and the following sub-paragraphs, using various testing methods. These methods may 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.