JOFOC_OTT_Hydromet_sign.pdf

Version 1.0

Source Selection Information – see FAR 2.101 and 3.104

SINGLE SOURCE DETERMINATION USING

SIMPLIFIED ACQUISITION PROCEDURES (SAP)

FOR AN ACTION NOT EXCEEDING THE SIMPLIFIED ACQUISITION THRESHOLD

(AUTHORITY: FAR 13.106-1(b)(1))

PR# 140800-24-0305

1. Agency and contracting activity. Department of Commerce, NOAA Office of Marine and Aviation Operations, Acquisition, Analysis, and Accountability Branch

2. Description of supplies or services required to meet agency needs (including the estimated value).

The current Eppley radiometers and the data acquisition RAD2 unit manufactured by RMR Co.

are no longer supported and the Kipp & Zonen radiometers (SMP-10 and SGR-4) are the recommended replacements. Accessories include a CVF4 Ventilation Fan for each radiometer used to improve temperature offsets associated with the measurement and reduce maintenance, a 25m Cable for power and signal distribution, and a PMU485 Smart Setup Hub for communications.

In a report released by the Intergovernmental Panel on Climate Change (2007) even small variations in solar radiation can have both global and regional-scale impacts on the Earth’s climate. Measuring the time and space variability of the solar radiation budget, which includes measures of net solar radiation and downwelling longwave radiation, using pyranometers and pyrgeometers, respectively, is central to understanding key questions regarding climate change as solar radiation is a driving factor in many of Earth’s climate related processes. Pyranometers measure the total solar irradiance or net solar radiation which comprises the diffuse horizontal solar irradiance from the sky and the direct normal solar irradiance from the sun integrated over a wavelength range of 285 to 3000 nm. Pyrgeometers measure the downwelling longwave radiation integrated over a wavelength range of 4.4 to 50 μm. CVF4 ventilation fans help to improve the accuracy of readings by lowering the thermal offsets, prevent precipitation, condensation, and dirt on the dome, and reduce the need for window cleaning and maintenance.

Kipp & Zonen Radiometers (SGR-4 pyrgeometer and SMP-10 pyranometer) and accessories (CVF4 Ventilation fan and Cables) are the recommended replacement of existing and obsolete Eppley radiometers in the fleet.

3. Identification of the single source or the brand name to be solicited.

Kipp & Zonen (brand name) OTT HydroMet Corp. (vendor) 22400 Davis Drive Sterling, VA 20164

(703) 406-2800

4. Supporting rationale. Only one source or brand name is reasonably available as detailed below:

Compatibility to existing systems or equipment - These units are direct replacements and match in fit, form, and function of existing units.

These units are replacements due to obsolescence of existing units. The Kipp & Zonen units match in fit and form, and exceed in function with advanced smart sensor features (fast response rate, onboard temperature corrections, sensor status and health), greater

PR # 140800-24-0305

Source Selection Information – see FAR 2.101 and 3.104 thermal stability (reducing error), and reduction of shortwave leakage (SGR-4) due to dome construction and materials. Additionally, the CVF4 ventilation fan lowers thermal offsets, prevents precipitation, condensation, and dirt on the dome and reduces the need for cleaning and maintenance.

5. Market Research.

It is recommended that the fleet move toward phasing out the use of the Eppley SPP pyranometer and PIR pyrgeometer and replace these radiometers with the Kipp & Zonen SMP- 10 pyranometer and SGR-4 pyrgeometer. While the Eppley provides high quality sensors, there are several features provided by the Kipp & Zonen sensors that are not available with the Eppley radiometers. Additionally, access to calibration and repair services for these sensors is questionable and future support may not be available. Kipp & Zonen is a company focused on providing high quality scientific instrumentation to measure solar radiation in applications ranging from the solar farm industry to marine research. Known for their technology measuring solar radiation, the pyranometers and pyrgeometers they produce are scientifically trusted, of high quality, and are known for precision and reliability. The pyranometers outlined herein meet the high-quality requirements of the World Meteorological Organization (WMO) and Baseline Surface Radiation Network (BSRN). In addition, they are categorized as ISO 9060 Spectrally Flat Class A pyranometers by the International Organization for Standardization (ISO).

Pyrgeometers do not currently maintain any classification status as no standardization currently exists, however, Kipp & Zonen pyrgeometers do comply with defined BSRN uncertainty standards of 5% or 10 W m-2, whichever is greater.

Unique to the Kipp & Zonen radiometers are summarized below:

SMP-10 Pyranometer:

Smart pyranometer digital interface allows for flexible connectivity, faster response rates, and automatic digital polynomial temperature corrections allowing for near real-time access to temperature corrected and directional response data

Solid-state dome heating to reduce impact of dew and condensation and internal humidity monitor

No moving parts and enhanced surge protection Individually optimized temperate compensation and sensors are supplied with both temperature and directional (cosine) response data Meets ISO 9060 standards as highest-Class A and is defined as suitable as a secondary standard Maintains a wide spectral range of 285 to 2800 nm Access to sensor health data in real-time

SGR-4 Pyrgeometer:

Smart pyrgeometer digital interface allows for flexible connectivity, faster response rates, and automatic digital polynomial temperature corrections allowing for near real-time access to temperature corrected and directional response data

Dome housing optimized to minimize directional error response and increase thermal stability further eliminating the need for dome temperature measurements or dome shading

Complies with BSRN defined uncertainty standards of 5% or 10 W m-2, whichever is greater

PR # 140800-24-0305

Source Selection Information – see FAR 2.101 and 3.104

Reduced shortwave leakage or solar radiation leakage due to optimized spectral cut-out wavelength, auto-correction of thermal offsets, and dome construction and materials

Access to sensor health data in real-time

In order to obtain accurate downward longwave irradiance, it is critical that the pyrgeometer have a precise temperature reading. The SGR-4 pyrgeometer from Kipp & Zonen performs an internal temperature correction to accurately and in real-time provide corrected data which limits potential issues with applying correction factors post data collection as well as errors associated with application of those correction factors. The main sources of error in Eppley pyrgeometers are due to differential heating of the sensor dome and body in addition to shortwave leakage through the dome filter which can lead to substantial errors in the event of moderate insolation (Weller, et al. 2008, Pascal and Josey, 2000). While data from the Eppley pyrgeometers can be corrected for these factors the SGR-4 provides corrections in real-time ultimately reducing errors on multiple levels. In addition to the aforementioned unique features of Kipp & Zonen sensors, utilizing smart radiometers eliminates the need for an interface to convert from analog to digital signals required with the Eppley systems further reducing electronic signal uncertainty.

The current data acquisition interfaces (RMR Co. RAD units) are no longer being manufactured or supported.

It is further recommended that each sensor include a CVF-4 ventilation fan that further protects the radiometer and helps to improve the accuracy of readings by lowering the thermal offsets, preventing precipitation, condensation, and dirt on the dome, and to reduce the need for window cleaning and maintenance. The ventilation fan provides a voltage and tacho output that will allow for remote monitoring of the fan during operations. These units are available through one distributor, OTT HydroMet Corp.

6. Technical/Requirements Representative Certification

I certify that this requirement constitutes the Government’s minimum needs and the supporting data provided herein is accurate and complete to the best of my knowledge and belief.

Katie Watkins-Brandt Date Section Chief of Science Services, MO

7. Determination

I hereby determine that the circumstances of this action deem only one source is reasonably available. This determination is accurate and complete to the best of my knowledge and belief.

Christopher Baker Contracting Officer

Date

7/18/2024

WATKINS-

BRANDT.KATIE.SUE.1618667622

Digitally signed by WATKINS-

BRANDT.KATIE.SUE.1618667622

Date: 2024.07.18 16:04:07 -07'00'

8/12/2024