Attachment_1_CSS_06-3218_N6426720R0040.pdf

CALIBRATION STANDARD

SALIENT SPECIFICATION

TEMPERATURE/HUMIDITY GENERATOR

MEASUREMENT SYSTEM

DEPARTMENT OF THE NAVY

METROLOGY AND CALIBRATION PROGRAM

CSS 06-3218

May 2019

CALIBRATION STANDARD

SALIENT SPECIFICATION

TEMPERATURE/HUMIDITY GENERATOR

MEASUREMENT SYSTEM

Prepared by: Lauren Orta

Physical / Mechanical Standards (MS 33)

Measurement Science Department

Naval Surface Warfare Center, Corona Division

DEPARTMENT OF THE NAVY

METROLOGY AND CALIBRATION PROGRAM

1.0 SCOPE

1.1 General. This specification is for a Temperature and Humidity Generator and Measurement System, herein referred to as the Temperature/Humidity System. The Temperature/Humidity System shall be capable of generating and measuring temperature, relative humidity, and dew-point temperature to support various temperature, relative humidity, and dew-point test instruments. For purposes of simplicity, unless otherwise specifically stated, the term “dew-point” will be used to denote dew-point and frost-point, as applicable (e.g., above 0 °C pertains to dew-point, while 0 °C and below pertains to frost-point), throughout this document.

1.2 Usage. The requirements of this specification are tailored to the intended use of the Temperature/Humidity System in a controlled environment.

2.0 OPERATIONAL REQUIREMENTS

2.1 Equipment Requirements. The Temperature/Humidity System shall be as specified in 2.1.1 through 2.1.22.

2.1.1 Temperature Range. The Temperature/Humidity System shall be capable of generating and measuring temperature ranges of -7 °C to +70 °C (20 to 158 °F).

2.1.2 Temperature Uncertainty. The Temperature/Humidity System shall be capable of generating and measuring the temperature range as specified in 2.1.1. The Temperature/Humidity System shall have an expanded uncertainty of ±0.031 °C (±0.056 °F), or better, using a coverage factor, k=2, and a level of confidence of 95%. The uniformity of the chamber shall be included in the Temperature Uncertainty.

2.1.3 Relative Humidity Range. The Temperature/Humidity System shall be capable of generating and measuring the relative humidity range of 10 to 95 %RH. Humidity “generation” is calculated using the temperature and pressure measurements at any given instant.

2.1.4 Relative Humidity Uncertainty. The Temperature/Humidity System shall be capable of measuring the relative humidity range as specified in 2.1.3. The Temperature/Humidity System must have an expanded uncertainty of ±0.5 %RH of indicated value, or better, using a coverage factor, k=2, and a level of confidence of 95%. The uniformity of the chamber shall be included in the Relative Humidity Uncertainty.

2.1.5 Dew-Point Temperature Range. The Temperature/Humidity System must, at a minimum, must be capable of measuring dew-point temperatures over the range -20 to +60 °C (-4 to + 140 °F). The Temperature/Humidity System shall be capable of measuring dew-point temperatures over the specified range without requiring the use of external chillers, or other means of refrigeration and/or cooling.

2.1.6 Dew-Point Temperature Uncertainty. The Temperature/Humidity System shall be capable of measuring dew-point temperature over the range specified in 2.1.5 with an expanded uncertainty of ±0.5 °C (±0.9 °F), or better, using a coverage factor, k=2, and a level of confidence of 95%.

2.1.7 Dew-Point and Frost-Point Indications. If the Temperature/Humidity System only provides a single indication at a time (e.g., in terms of dew-point or frost point), then the Temperature/Humidity System shall be capable of distinguishing between dew-point temperature and frost-point temperature over the range specified in 2.1.5, and perform all necessary conversions and/or calculations to ensure compliance with the uncertainty requirements specified in 2.1.6. Alternatively, this requirement is met if the Temperature/Humidity System provides both frost-point and dew-point indications, each meeting the uncertainty requirements specified in 2.1.6.

2.1.8 Flow Rate. The Temperature/Humidity System shall be capable of delivering a flow rate of 40 liters per minute (LPM), or 84.75 cubic feet per hour (CFH), or greater, without the use of an external source (e.g., blower).

2.1.9 Resolution/Readability. The Temperature/Humidity System shall have a resolution of 0.01 °C/°F for temperature and dew-point temperature whereas relative humidity will have a resolution of 0.01 %RH, or better, over the range specified in 2.1.1, 2.1.3, and 2.1.5 for temperature, relative humidity, and dew-point, respectively.

The Temperature/Humidity System shall have a readability of 0.1, or better, for flow measurements. The Temperature/Humidity System shall have a readability of 0.1 or better for moisture measurements in units of parts-per-million by volume (PPMv), and parts-per-million by weight (PPMw).

2.1.10 Units of Measurement. The Temperature/Humidity System shall be capable of measuring temperature and dew-point temperature in units of °C and °F. It shall also be capable of measuring relative humidity in units of %RH. Additionally, the Temperature/Humidity System shall provide flow indications in units of liters per minute (LPM) and cubic feet per hour (CFH). The Temperature/Humidity System shall provide moisture measurements in units of parts-per-million by volume (PPMv) and parts-per-million by weight (PPMw).

2.1.11 Digital Interface. The Temperature/Humidity System shall have a digital interface that permits the operator to program and control each device function, including entering set-point values, changing units of measurement, and providing digital indications of temperature, relative humidity, flow, moisture, and frost-point / dew-point temperature. The temperature and dew-point temperature shall stabilize within ±0.1 °C/°F of the set-point value while relative humidity shall be within ±0.1 %RH. The digital interface shall also permit easy access to various menus for system settings, calibration, alignment, and creating UUT profiles for automated calibration. The primary power control and other non-measurement functions do not need to be controlled through the digital interface.

2.1.12 Serial Ports. The Temperature/Humidity System shall have multiple serial ports that are capable of connecting to at least 4 Units Under Test (UUTs) at a time to allow serial data exchange.

2.1.13 Access Port. The Temperature/Humidity System shall have at least one access port no smaller than 1-inch in diameter and no larger than 2 inches. This will allow UUT sensors to be inserted into the Temperature/Humidity System chamber while the main body of the UUT is outside the Temperature/Humidity System. The Temperature/Humidity system must come with a foam insulator, or similar, that can be used to plug the access port when it is not in use.

2.1.14 Digital Setting Repeatability. The Temperature/Humidity System shall have a digital setting repeatability of ±0.1 °C/°F, or better. In addition, it shall also have a digital setting repeatability of ±0.1 %RH, or better.

2.1.15 Digital Setting Control. Upon inputting a set-point value (e.g., 10 °C) the Temperature/Humidity System shall be capable of achieving any value within the range specified in 2.1.1, 2.1.3, or 2.1.5 and stabilize within the digital setting repeatability given in 2.1.14 without additional operator intervention. The system shall be capable of controlling and maintaining the set-point value once it is achieved.

2.1.16 Multiple UUT Connections. The Temperature/Humidity System shall be capable of connecting to a minimum of four UUTs at a time, and retrieving all calibration information (e.g., dew-point temperature) that is necessary to verify each UUT’s performance. The Temperature/Humidity System shall be capable of providing a side-by-side comparison of each UUT against the Temperature/Humidity System measurements in a graphical and/or tabular format over the entire duration of the UUT(s) calibration.

2.1.17 Automated Calibration. The Temperature/Humidity System shall be capable of creating test profiles for UUTs, and enable automated calibration of UUTs that are compatible with the communication protocols described in 2.1.16. At a minimum, the Temperature/Humidity System shall enable the operator to program up to 10 test points, the stabilization period at each test point, and the flow rate at each test point. Once the process is initiated, it shall not require additional input and/or intervention from the operator. The operator shall have the ability to view all calibration measurements anytime during calibration, and at the end of calibration, for both the UUT(s) and the Temperature/Humidity System at each test point for verification purposes.

2.1.18 Calibration and Alignment. The Temperature/Humidity System shall satisfy the calibration and alignment requirements indicated in paragraphs 2.1.18.1 and 2.1.18.1.

For the purpose of this calibration specification, the term “Calibration” refers to the process of comparing the Temperature/Humidity System with a calibration standard to determine the error at specified test points. The term “Alignment” refers to the process of characterizing and adjusting the Temperature/Humidity System to cause it to meet its performance specifications.

2.1.18.1 Calibration Standards. The Temperature/Humidity System shall be capable of being calibrated and aligned by standards that are commercially available to permit Navy organic support.

2.1.18.2 Calibration/Alignment. The Temperature/Humidity System shall be capable of being calibrated and aligned by the Navy, and in accordance with paragraph

2.1.18.1. The Temperature/Humidity System shall be provided with all necessary instructions and firmware necessary to calibrate and align the equipment so that the equipment meets its performance specifications after repair or due to the equipment failing calibration.

a. The calibration and alignment software instructions shall be part of the Temperature/Humidity System firmware.

b. Alignment data. If the equipment has alignment data stored in memory (e.g., EEPROM, data files, DACs etc.) that is necessary for the equipment to meet its performance specification and modification of this alignment data is necessary after repair of a calibration failure, the equipment shall be designed and information provided so that the alignment can be performed by the Navy.

2.1.19 Chamber Dimensions: The chamber is the location in the Temperature/Humidity System where the UUT will be placed. The Temperature/Humidity System chamber shall be 10 inches by 10 inches by 10 inches, or greater.

2.1.20 Viewing Window Dimensions: The Temperature/Humidity System shall have a viewing window that allows the user to examine the indications of an UUT placed into the chamber for data collection purposes. The dimensions of the viewing window on the Temperature/Humidity System shall be 5 inches by 5 inches, or greater.

2.1.21 Electrical Power. The Temperature/Humidity System shall operate at the nominal voltage of 220 Vrms (±20 Vrms), and a nominal, single-phase, frequency of 60 Hz (±5 Hz). The performance and accuracy of the Temperature/Humidity System shall not be adversely affected with changes in voltage and frequency, as follows;

(a) steady-state voltage-tolerance of ±10%, and (b) steady-state frequency-tolerance of ±5%.

2.1.21.1 Power Cord. Any power cord(s) that are required shall be provided with the Temperature/Humidity System.

2.1.22 Portability: The Temperature/Humidity System shall be designed to be easily moved within the calibration facility. This can be accomplished by wheels, or similar, attached to the frame of the system, itself, or a cart holding/housing the Temperature/Humidity System.

3.0 GENERAL REQUIREMENTS

3.1 Environmental Requirements. The Temperature/Humidity System environmental performance requirements shall be as specified below in 3.1.1 through 3.1.3. It shall conform to the performance requirements specified in Section 2 when subjected to the environmental conditions of this specification.

3.1.1 Warm-up. The Temperature/Humidity System shall comply with the specified performance requirements after a 10-minute warm-up period preceded by a 1-hour not operating temperature stabilization period.

3.1.2 Temperature Operating. The Temperature/Humidity System shall conform to the specified performance requirements while being operated at temperatures over the range of 60 ºF to 85 ºF, inclusive.

3.1.3 Humidity. The Temperature/Humidity System shall conform to the specified performance requirements for conditions where the relative humidity is within 20 to 60 %RH and the temperature is within 60 ºF to 85 ºF.

3.2 Calibration Certificate. The Temperature/Humidity System shall have a current calibration certificate or label, indicating that the calibration is traceable to the National Institute of Standards and Technology (ANSI Z-540, 17025) or equivalent recognized organization and standard when delivered to the Navy.

3.3 Reliability. Unless otherwise specified, the design of the equipment shall be such that under normal use and operation the equipment does not fail within 1500 hours of operation with a statistical certainty of 95%. The manufacturer shall provide a summary of maintenance or warranty records to establish the validity of the statistical assertion. Records of the actual equipment model shall be used, unless the Government authorizes the substitution of records from a similar model, due to the lack of sufficient supporting documentation on the offered equipment. The manufacturer shall be able to reasonably establish the claim that the offered equipment shall provide reliability similar to the model used to provide substitute records.

3.4 Calibration Interval. The recommended calibration interval of the Temperature/Humidity System shall be at least 12 months. At the end of this interval, a minimum of 85% of the equipment shall remain in tolerance.

3.5 Technical Manuals. A copy of an operation and maintenance manual shall be provided with the Temperature/Humidity System.

3.6 Marking. The Temperature/Humidity System shall be marked in a manner that does not adversely affect safety or performance. At a minimum the manufacturer, model number, and serial number shall be identified on the Temperature/Humidity System.