Attachment 1 SOW.pdf

19 August 2026

Balance Thermocouple Power Sensors

I. Background The National Institute of Standards and Technology (NIST) plays a foundational role in maintaining the nation’s measurement infrastructure, particularly in the electrical power sector where accurate metering underpins more than $400 billion in annual U.S. electricity sales. To ensure fairness and consistency in this vast marketplace, NIST provides SI-traceable calibration services for power and energy meters, allowing utilities, regulators, and industries to rely on a single authoritative source for measurement accuracy. As electrical systems evolve— driven by smart-grid technologies, high-efficiency power electronics, and increasingly complex RF environments—the demands placed on NIST’s measurement capabilities continue to grow. Traditional RF AC-DC transfer standards face significant challenges at higher frequencies, where impedance mismatch effects introduce larger uncertainties and limit the precision of calibration services. To address these limitations, NIST is working to modernize its RF AC-DC measurement services through the development and implementation of wideband power sensors, which enable accurate, low-uncertainty measurements across a much broader frequency range. These sensors reduce mismatch-related errors, improve bandwidth performance, and support the traceability required for emerging technologies in communications, aerospace, defense, renewable energy, and advanced manufacturing.

Strengthening this measurement infrastructure is essential not only for technical accuracy but also for sustaining U.S. industrial competitiveness, ensuring reliable commerce, and supporting the nation’s transition toward more advanced and interconnected electrical systems.

II. Scope The Applied Electrical Metrology group at NIST has a requirement for quantity two (2) units of balance thermocouple sensor for RMS detection of type N connectorized voltage signals over the DC to 18 GHz range and Qty one (1) unit of wideband power sensor of 2.4 mm connectorized voltage signals over the DC to 50 GHz frequency range and 2V to 10 mV RMS amplitude ranges, for a total of three devices and the associated software the provides interface to use the devices with a lab computer. The devices need to have two thermoelements and can be used in a null arrangement.

III. Minimum Requirements:

The system shall meet or exceed the minimum requirements identified below. All items must be new. Used or remanufactured equipment will not be considered for award. Experimental, prototype, or custom items will not be considered. The use of “gray market” components not authorized for sale in the U.S. by the Contractor is not acceptable. All line items shall be shipped in the original manufacturer’s packaging and include all original documentation and software, when applicable.

CLIN 0001:

Description: Keysight N8481S Balance thermocouple sensor for DC to 18 GHz Quantity: 2 Technical Specifications:

1. Shall contain two thermoelements, and can be used in a null arrangement

2. Shall have the frequency range DC to 18 GHz

3. Power range of -35 to +20 dBm

4. Connector N-type, male

5. Maximum unput RF power: for CW signal: 316 mW/+25 dBm at 50 Ohm impedance and for Modulated Pulse Signal: 15 W/+42 dBm (2 microsecond)

6. Maximum input DC power: 316 mW/+25 dBm

7. Typical load resistance measured at the coaxial connector of 50 Ohms

8. Typical DC heater resistance measured at the DC connector of 50 Ohms

9. Thermocouple resistance: Single (RF side: 8 kOhms) and Dual (RF and DC:

16-17 kOhms)

10. Thermocouple sensitivity for RF connector at 25 C: 1070 mV/W: DC connector at 25 C: 1050 mW/W

11. Delivered with calibration with a calibration factor uncertainty of not more than 1.75 % at 18 GHz

12. SWR of not more than 2.0 at highest frequency at the operating temperature

13. One device will be delivered with a 5 ft power sensor cable

14. One device will be delivered with a 10 ft power sensor cable

CLIN 0002:

Description: Keysight N8487S Balance thermocouple sensor for DC to 50 Ghz Quantity: 1 Technical Specifications:

1. Shall contain two thermoelements, and can be used in a null arrangement

2. Shall have the frequency range of DC to 50 GHz

3. Power range of -35 to +20 dBm

4. Connector 2.4 mm, male

5. Maximum input RF power: for CW signal=316 mW/+25 dBm at 50 Ohm

6. Maximum input DC power: 316 mW/+25 dBm

7. Typical load resistance measured at the coaxial connector of 50 Ohms

8. Typical DC heater resistance measured at the DC connector of about 97 Ohms

9. Thermocouple resistance: Single (RF side: 8 kOhms) and Dual (RF and DC:

16-18 kOhms)

10. Thermocouple sensitivity for RF connector at 25 C: 1080 mV/W; DC connector at 25 C: 2070 mV/W

11. Delivered with calibration with a calibration factor uncertainty of not more than 1.75 % at 50 GHz and not more than 2.0 % at 18 GHz

12. SWR of not more than 5.0 at the highest frequency at the operating temperature

CLIN 0003:

Description: Keysight N8480SBSA Balance thermocouple power sensor software Quantity: 1 Technical Specifications:

1. The software will provide a convenient interface to work with the devices specified in Line 0001 and Line 0002 via USB connection

2. Shall work with Windows 11 and updatable with future Windows operating system versions.

3. The software can be used for the devices in Line 0001 and Line 0002 and transportable to different computers.

4. If software is issued with a license, that the license is perpetual

5. If software is issued with a license, that it can be used with any one device at a given time, via a dongle or similar device.

IV. Deliverables Deliverable

Number Description Quantity Due Date

Place of Delivery

Keysight N8481S with specifications described in Line 0001 with one 5 foot sensor cable and the other with one 10 foot cable

2 60 Days ARO NIST Gaithersburg

2 Keysight N8487S with specifications described in Line 0001 and a 5 foot sensor cable

1 60 Days ARO NIST Gaithersburg

3 Keysight N8480SBSA Balance Thermocouple Power Sensor Software Application

1 60 Days ARO NIST Gaithersburg

Standards of Acceptance: The NIST POC or COR shall review all the above deliverables and respond with an acceptance or request for revision email to the Contractor Point of Contact (POC) within 14 days of receipt of deliverables. This section applies to deliverables which must be reviewed and approved for acceptances (e.g., draft plans, drawings, etc.)

V. Delivery Delivery shall be FOB Destination (or equivalent terms, such as INCOTERMS Delivered Duties Paid) are required and shall occur not later than (NLT) 60 days

ARO.

FOB Destination means: The contractor shall pack and mark the shipment in conformance with carrier requirements, deliver the shipment in good order and condition to the point of delivery specified in the purchase order, be responsible for any loss of and/or damage to the goods occurring before receipt and acceptance of the shipment by the consignee at the delivery point specified in the purchase order; and pay all charges to the specified point of delivery. The contractor shall deliver all Line Items to:

The National Institute of Standards and Technology 100 Bureau Drive, Building 220, room B153 Gaithersburg, MD 20899-8172

VI. Inspection and Acceptance In addition to the inspection and acceptance terms articulated in 52.212-4, the Government reserves the right to perform such performance tests and evaluations as defined below to verify specified system performance. Such tests and evaluations, if performed, shall be conducted within the environment that the system is to be operated. The Contractor has the right to be present during the tests and evaluations, if performed, at the Contractor’s expense.

NIST will perform basic functional tests using NIST Applied Electrical metrology instruments to verify that the balance thermocouple power sensors perform according to specifications.

The Government will test, inspect, and accept the equipment onsite within 14 days. A visual inspection of the balance thermocouple power sensors will be performed by the NIST Subject Matter Expert (SME) to identify surface defects or any form of indication that the devices were damaged during transport to NIST.

The Government shall have sole discretion to require repair or replacement of damaged and/or nonconforming supplies at no cost to the Government. The Government at any time prior to acceptance shall reject the Current transformer due to defects and/or nonconformance.

VII. Warranty The Current transformer shall be new (not refurbished or reconditioned) and covered by the original manufacturer’s full warranty with service provided by that manufacturer’s organization. The contractor shall warrant the entire system for a minimum of 1 year after receipt of the equipment and shall be in accordance with terms in FAR 52.212-4.

VIII. Payment Schedule The Contractor shall be paid, in accordance with Net 30-day payment terms, upon receipt and acceptance of a proper invoice, in accordance with the following schedule:

1. 100% after acceptance by the TPOC, AND

2. After the successful completion of the testing requirements set forth in this document

NOTE: Partial shipments and partial invoices will not be accepted, unless otherwise requested and accepted by the Contracting Officer prior to award offer. Proposed payment schedules shall be submitted with vendor’s response to the RFQ for consideration.