Precision Pressure Calibrator QA_N6426725R0003.docx

Updated: 15 October 2025 N6426725R0003 Precision Pressure Calibrator Sources Sought Notice Q&A

1) Section 3.1.1.5c of the CSS description states that operation must be seamless from vacuum to 10,000 psi. This would not be possible with a two-controller solution. This requirement would be handled by a solution similar to the 4322 but with better uncertainty. Please confirm that your objective is to purchase a solution that is a single controller that provides seamless operation from vacuum to 10,000 psi or if a two-controller system one from vacuum to 3000 psi and the other from atmospheric pressure (ATM) to 10,000 psi is preferable.

RESPONSE: We are more interested in a system that can seamlessly transition from vacuum to 10,000 psi. However, NAVSEA may consider a maximum of a 2 controller system. One system should be capable of controlling and measuring pressure from vacuum to a MINIMUM of 3000 psi, while the second system covers a overlapping range up to 10,000 psi. The accuracies shall still match those listed in the CSS.

2) Section 3.1.2.5 indicates that the burst pressure of the CPS should be 40,000 psi. With supply pressure likely limited to 10,000 psi from an intensifier is there really a need to specify a burst pressure of 40,000 psi. I’m not sure we could prove that.

RESPONSE: This is a safety requirement, we cannot consider options that do not meet the 4X burst pressure.

3) Section 1.1 indicates that the equipment “is intended to be used by Navy personnel in shore-based laboratories”. Section 1.2 appears to contradict section 1.1 by stating that the equipment will be subjected to operational conditions aboard land, sea and air vehicles. Are these conflicting statements or am I misunderstanding something?

RESPONSE: The equipment will only be on Shore-Based laboratories.

4) The requirement is to control and measure up to 10,000 psi and to include a supply pressure hose (CSS section 3.1.2.3.1). Section 3.1.1.1 indicates that “the pressure media shall travel from the pressure source;;;;”, but does not indicate if an accessory is required to generate the supply pressure or if it the Navy will provide the source. Please specify.

RESPONSE: The Navy will provide a pressure source for the equipment.

5) §3.1.1.7 Range & Accuracy: Will compliance be verified through full end-to-end system testing of the delivered PPC, or will it be acceptable to demonstrate accuracy using certified smart transducer calibration data combined with documented controller uncertainty contributions?

RESPONSE: We will verify performance specifications by an end to end acceptance test of the delivered PPC. This would require the documentation (calibration data with documented controller uncertainty contributions).

6) §3.12 Calibration Interval: Will the ≥85% in-tolerance metric at 12 months be validated via accelerated life testing, or is historical reliability data and prior production evidence acceptable?

RESPONSE: This requirement may be verified using historical reliability data and prior production evidence. Please provide documentation that include a list of NIST Traceable standards used to gather this data (Typical for a Report of Calibration, ROC).

7) §3.1.1.1 Pressure Media: Does “prevent reverse flow” apply to all upstream media (nitrogen/air) from back-flowing into the controller, or only to potentially contaminated return media routed through the CPS?

RESPONSE: “Prevent reverse flow” applies to all upstream media from back flowing into the controller. The CPS is an accessory that adds extra protection to the main controller and can be used to collect the contaminants and safely dispose of.

8) §3.1.1.4 Contamination Prevention: Should the contamination prevention system be integrated within the main instrument, or may it be delivered as a separate accessory module if it is automatic, meets proof/burst ratings, and interfaces to the return circuit?

RESPONSE: The CPS may be delivered as a separate accessory that meets all the requirements.

9) §3.4 Interfaces (SCPI): Must identical SCPI command coverage be implemented across all provided interfaces, and are there latency/jitter thresholds for closed-loop control via Ethernet?

RESPONSE: There shall be similar SCPI commands among all the provided interfaces. Any differences in commands will require documentation that details how to establish connection to and control the equipment. There are no requirements for latency and jitter thresholds for Ethernet connections, however, all connections are required to be stable and reliable.

10) §3.5.1–3.5.3 Power Interruptions: Must the instrument return to the prior control state (setpoint, mode) automatically after a power interruption, or is it sufficient to retain configuration and require operator re-enable?

RESPONSE: It is sufficient to retain configuration prior to the power loss. There should be an automated operation to safely relieve pressure if power loss occurs at high pressure.

11) §3.6 Physical Size/Weight: How does the Government define a “main component”? For example, is the controller one component and CPS/vacuum pump separate, allowing multi-case packaging so long as each case meets the 45-lb limit?

RESPONSE: Correct, controller, CPS, and vacuum pump are considered separate components. The PPC system shall be designed for benchtop use so it shall be setup and operated by one person.

12) §3.1.2 Hoses & Vacuum Pump: Please confirm acceptable hose materials for clean vs. contaminated circuits, and the required tag format for pressure ratings. May the vacuum pump be packaged in a separate case to meet the 44-lb/handle limit?

RESPONSE: Any hose material that meets the requirements set in 3.1.2.3, maintain those requirements when exposed to pressure media contaminated with fluids listed in 3.1.1.4 and does not introduce foreign object debris (FOD) into the system after repeating use, shall be acceptable. Both contaminated and clean hoses may be the same material, initially be cleaned, and shall be color coated per section 3.1.1.4. Per section 3.1.2.3, a metal tag shall list working and burst pressure of the hose and permanently attached to the hose. Vendors may also include an individual part number on this tag as well.

Per response on item 7, the vacuum pump is considered a separate component and may be packaged in a separate case to meet weight requirements.

UPDATED QUESTIONS 10/9/2025:

13) Re: 3.1.1 The assumption is that “dynamic” refers to using the PPC to control to a specific pressure while “static” is simply using the PPC to measure existing pressure without regulation. Is this correct? Is a controlled “ramp” function required (a prescribed rate of pressure increase or decrease)?

RESPONSE: Dynamic mode refers to actively controlling a pressure within a hold limit around the set point until it stabilizes. Static mode refers to applying pressure to a set point and once it reaches the target, it stops control allowing the system to stabilize on its own within a hold limit. It would be ideal to control the ramp rate to a set point but there is no requirement.

14) Re: 3.1.1.1, 3.1.1.4 and 3.1.1.5.d Does potentially contaminated input media (i.e. N2 that has come into contact with the TI) need to be prevented from backflow? It will pass through several filters but there must be a direct line between the control valve, transducer, and TI to properly control pressure during the calibration process. One the calibration process has finished we can isolate the fluid between the CPS and TI and purge all of that media but during calibration there will be venting via the control valve. Below is a very basic block diagram of a hypothetical system. Is this sufficient for your purposes?

RESPONSE: Per the schematic, it will be sufficient for our end use and to follow up, will the pressure isolation system further prevent contamination from reaching any sensitive components? The equipment must be design to be used to calibrate a variety of Test Instruments that may be exposed to one or more of the fluids listed in 3.1.1.4.

15) Re: 3.1.3.4 “The PPC shall maintain system cleanliness and prevent cross contamination of TIs. There shall be minimum cleaning required for either pneumatic or hydraulic system TIs prior to calibration and no cleaning no cleaning required for after calibration to prevent cross contamination of the TI’s and/or the PPC”. What does “minimal cleaning” refer to? There will always be a connection (QD, plug, probe, NPT etc.) between the CPS and the TI. If the TIs are not clean when calibrated, cross contamination could occur at the connection point.

RESPONSE: “Minimal Cleaning” refers to basic cleaning of the TI done using DI water, soap, isopropyl alcohol (IPA), lint free wipes to remove major contaminants as opposed to thorough cleaning with specialized solutions at a component level in order to meet a cleanliness standard. Any further contaminants would be captured in the CPS and disposed of at the end of testing. CPS should also be easily cleaned to be used quickly in testing.

16) Re: 3.3.6 Front panel display indicators: “All display indicators shall be discernible at viewing angles from 0 degrees to 45 degrees.”

Is this laterally? Vertically? Where is the zero (looking straight down, looking horizontally across the horizon)? In general, is the preference for users standing and looking down on the panel or sitting and looking just below eye level at the panel?

RESPONSE: 0° to 45° viewing angle is a minimum requirement and is applied both laterally and vertically where 0° is looking directly in front of the display (perpendicular or normal to the display). The equipment shall be designed for bench top use, so the display shall be easily viewable when standing or off to the side of the equipment.

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