Differential Thermal Analysis (DTA) System - Components.

THIS IS FOR INFORMATIONAL PURPOSES ONLY. Under the authority of FAR 13.106, the USDA FS Northern Research Station – 07, Vermont intends to award to Campbell Scientific Inc. on a sole source basis, a Firm Fixed Purchase Order (PO) for a Differential Thermal Analysis (DTA) System – components to construct a system in house.

A differential thermal analysis (DTA) system is a specialized laboratory apparatus used for measuring plant cold hardiness and designed to detect cellular-level freezing events within plant tissues. The system works in conjunction with a protocol of sample handling, manipulation of temperature via a programmable cold chamber, and a freezing detection system (DTA):

1. Sample preparation: Plant tissues, such as floral buds, are carefully collected and prepared for analysis. The samples are often placed in small aluminum foil packets or directly on thermoelectric modules.
2. Temperature control: The system includes a temperature-controlled chamber or cooling plate that can lower the temperature at a controlled rate, typically mimicking natural freezing conditions.
3. Thermoelectric modules: The samples are placed on thermoelectric modules (TEMs) or thermocouples that can detect minute temperature changes.
4. Multiplexers: A series of multiplexers are needed to monitor many TEMs.
5. Reference sample: A reference sample, usually an inert material that doesn't undergo phase changes, is placed alongside the plant tissue samples for comparison.
6. Cooling process: Plant tissue and reference samples are exposed to gradually decreasing temperatures in a cold chamber, often at a rate of 2-4°C per hour, to simulate natural freezing conditions.
7. Exotherm detection: As plant tissues freeze, they release heat (exotherms). The DTA system detects these exotherms as temperature differences between the plant tissue sample and the reference.
8. Data acquisition: A logging system continuously records the temperature data and identifies exotherms, which appear as peaks on a temperature-time graph.

Our work unit already has a cold chamber that can accommodate steps 2 and 6.

Specific required features include:

• Nickel coated Potted TEMS with dimensions 12 mm by 26 mm
• Ability to multiplex 96 TEMS and fit within a 15” by 15” freezer chamber
• Trays to hold up to 32 temps to create a modular system
• High-resolution multiplexers with a 24-bit analog-to-digital converter, enabling low-noise performance and superior analog measurements.
• High-speed multiplexer that can achieve a maximum capture rate of 30 kHz on a single channel for 2.5 seconds or less.
• Multiplexers that are solid state to withstand millions of measurements over the life of the unit.

THIS IS NOT A REQUEST FOR COMPETITIVE PROPOSALS. This is a notice of intent to solicit and award a sole source contract under statutory authority in accordance with both 41 U.S.C. 253(c)(1) and FAR 13.106-1(b)(1)(i).  Proposed award date on or about 01 August 2024 with an estimate 45-day shipping after receipt of order.  The Proposed contract action is for supplies which the Government intends to solicit and negotiate with only one source under the authority of FAR 13.106-1 (b)(1)(i).

Interested persons may identify their interest and capability to respond to the requirement.  This notice of intent is NOT a request for proposals or quotations; it is a market research tool being utilized to determine the availability and adequacy of potential sources prior to awarding the contract. A determination by the Government not to compete this proposed action based upon responses to this notice is solely within the discretion of the Government. All inquiries on this action can be submitted in writing via e-mail to Jonathan Betancur at Jonathan.Betancur@usda.gov no later than 25 July 2024 at 1400 hours EST. All information shall be furnished at no cost or obligation to the Government.

Contract type will be a Firm-Fixed Price. NAICS code is 334516, Analytical Laboratory Instrument Manufacturing

NOTICE OF INTENT TO SOLE SOURCE