Attachment 06 - Item Specification for the Near Background Survey Meter.pdf

PRF TBD

Original Design Activity

CAGE Code 0FW37 23 September 21

PERFORMANCE SPECIFICATION

ITEM SPECIFICATION

FOR THE

NEAR BACKGROUND SURVEY METER

Revision 2

NAVSEA Comments Incorporated

Prepared by:

Naval Surface Warfare Center Carderock Division

9500 MacArthur Boulevard West Bethesda, MD 20817

SUBMITTED BY:

Adrienne Capil Engineer

NSWCCD

APPROVED FOR USE AS

FUNCTIONAL BASELINE BY:

Technical Warrant Holder

NAVSEA 04ND

CAPIL.ADRIEN

NE.J.11733299

Digitally signed by

CAPIL.ADRIENNE.J.1173

329900 Date: 2021.09.27 11:58:38 -04'00'

Item Specification for the Near Background Survey Meter

1. Scope The document includes the item specification for the near background survey meter. The instrument will be used by the Navy to monitor background radiation levels.

2. Applicable Documents

2.1 American National Standards Institute (ANSI) N42.17C-1989, “Performance

Specifications for Health Physics Instrumentation – Portable Instrumentation for Use in Extreme Environmental Conditions”

2.2 ANSI N42.17A-2003, “Performance Specifications for Health Physics Instrumentation – Portable Instrumentation for Use in Normal Environmental Conditions”

2.3 Military Standard (MIL-STD)-461G, “Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment”

2.4 MIL-STD-810H, “Environmental Engineering Considerations and Laboratory Tests”

2.5 ANSI Z540.2-1997, “American National Standard for Expressing Uncertainty – United

States Guide to the Expression of Uncertainty in Measurement”

2.6 Military Details (MIL-DTL)-15024G, “General Specification for Plates, Tag, and Bands for

Identification of Equipment”

3. Requirements Where applicable, an objective requirement is identified in a set of braces { }. All other specification items are threshold requirements.

3.1 Environmental

3.1.1 The instrument shall withstand 40 {10} – 93 {95} percent (%) relative humidity (RH) conditions in accordance with ANSI N42.17A-2003, Section 9.3.1.

3.1.2 The instrument shall operate within the temperature range of -10 degrees Celsius (°C)

{-20 °C} to 50 °C (14 degrees Fahrenheit (°F) {-4 °F} to 122°F) in accordance with ANSI N42.17A-2003, Section 9.1.1.

3.1.3 The instrument shall have a maximum altitude of 15,000 feet for storage and transport in accordance with MIL-STD-810H, Method 500.6.

3.1.4 The instrument shall continue to operate after a drop test in accordance with ANSI

N42.17C-1989, Section 8.11.1.

3.1.5 The instrument shall have an ingress protection (IP) rating of at least IP64 and in accordance with ANSI N42.17C-1989, Sections 8.12.1 and 8.13.1.

3.1.6 The instrument’s response when exposed to a temperature change from 22 °C to -10 °C, -10 °C to 22 °C, 22 °C to 50 °C, and 50 °C to 22 °C in less than five minutes shall be within 20% of the response at 22 °C in accordance with ANSI N42.17A-2003, Section 9.2.1.

3.1.7 The instrument shall conform to the Electromagnetic Interference (EMI) susceptibility and emission requirements stated in MIL-STD-461G. Procurement shall meet all of the “applicable” and “limited” requirements of Table V Navy, Ground platforms.

3.1.8 The instrument shall operate in fuel-air explosive atmospheres without causing ignition in accordance with MIL-STD-810H, Method 511.7.

3.2 Features

3.2.1 The maximum dimensions of the instrument, including external probe (if applicable), shall be 5 inches (in) x 13 in x 10 in.

3.2.2 The maximum weight of the instrument, including external probe (if applicable), shall be 7 pounds.

3.2.3 The minimum measurement range for exposure rate of the instrument shall be 1.0 microRoentgen per hour (μR/hr) to 1,000 μR/hr.

3.2.4 The minimum selectable measurement units shall be μR/hr or microrem per hour

(μrem/hr).

3.2.5 The minimum photon energy response range of the instrument shall be 40 kilo-electron volts (keV) to 1.5 Mega-electron volt (MeV).

3.2.6 The instrument shall have a warm-up time of less than ten {one} minute(s) in accordance with Table 1 of ANSI N42.17A-2003.

3.2.7 The instrument shall not require cooling for detector function.

3.2.8 The instrument shall not have an attached source of radiation.

3.2.9 The instrument shall maintain battery power for at least 50 {100} hours under normal operating conditions. Batteries shall be commercially available and shall not be lithium based.

3.2.10 The digital instrument display shall be capable of being read from a distance of two feet

{three feet}, with a maximum error of 10% (90% correct recognition of display) in an ambient light intensity of 10+5 lux (full sunlight) and 10-3 lux (darkness). The display may be illuminated to meet this requirement.

3.2.11 The instrument shall meet the following general characteristics for health physics instrumentation: scaling factors, ease of decontamination, markings, battery status indication, protection of switches, zero set, battery power, and battery power indication described in ANSI N42.17A-2003, Section 5.

3.2.12 The instrument shall support surveying behind an obstacle without using an audio signal.

If the instrument includes a control unit and an external probe, the cable length shall be four feet to five feet to support this application. If the instrument has an embedded probe, then the dose rate readings acquired behind an obstacle shall be available for later retrieval.

3.2.13 The instrument shall include an audible signal indicating radiation interactions. The instrument may include an adjustable volume.

3.2.14 The instrument shall include a silent mode to permit operation with no audible signal.

3.2.15 The instrument shall measure exposure rate within ± 20% {±10%} accuracy for energies at and above 100 keV and within – 40% to +20% {10%} accuracy for energies below 100 keV when exposed over the minimum measurement range of exposure rates.

3.2.16 The response of the instrument to Cobalt-60, Cesium-137, Americium-241, and 80 keV photon radiation at any angle not exceeding 45 degrees from the direction of maximum response of the instrument shall be not less than 80% of this maximum response. At an angle of 90 degrees from the direction of maximum response, the mean instrument reading shall be not less than 50% {80%} of the maximum response in accordance with ANSI N42.17A-2003, Section 7.7.1.

3.2.17 Instrument shall provide a stable response in a low radiation environment of 10 μR/hr {3 μR/hr}. The response is considered stable when the coefficient of variation, determined 0.3.

3.2.18 The instrument shall be capable of responding to, and recovering from, a rate of exposure step change of at least 5μR/hr from an ambient radiation environment of less than or equal to 15 μR/hr {10 μR/hr} to a low radiation environment in less than 15 seconds.

3.2.19 The instrument shall not subtract any signal from ionizing radiation within the minimum photon energy response range, including signals from natural background radiation sources.

3.2.20 In addition to the rate meter function, the instrument shall also provide a scaler function with the following:

- User-configurable preset time and preset count modes.

- Gross counting mode {User-configurable energy/pulse height window counting mode and gross counting mode.}

- Clear indication of an overflow condition.

4. Verification

4.1 Environmental

4.1.1 Humidity testing shall be performed in accordance with ANSI N42.17A-2003, Section

9.3.2. The instrument will conform to the specification if the instrument response is within 15% of the mean instrument response at 40% RH during and after exposure to a noncondensing RH range of 40% - 93% {10% - 95%} at 30°C.

4.1.2 Temperature testing shall be performed in accordance with ANSI N42.17A-2003, Section 9.1.2. The instrument will conform to the specification if (1) the mean instrument response over the temperature range from 0 °C to 40 °C is within 15% of the mean response determined at 22 °C and (2) if the mean instrument response over the temperature range from -10 {-20} °C to 0 °C and 40 °C to 50 °C is within 20% of the mean response determined at 22 °C.

4.1.3 Maximum altitude storage and transport testing shall be performed in accordance with MIL-STD-810H, Method 500.6, Section 4, Procedure I. The instrument will conform to the specification if the instrument continues to operate in accordance with the performance specification following exposure to pressures associated with an altitude of 15,000 feet above sea level. The maximum altitude shall be held for one (1) hour and the altitude change shall not exceed 10 meters per second.

4.1.4 Drop testing shall be performed in accordance with ANSI N42.17C-1989, Section 8.11.2.

The instrument will conform to the specification if the instrument continues to operate in accordance with the performance specification after a fall of 1 meter onto a concrete surface. After a series of five tests, the instrument response shall vary less than or equal to 15% compared to instrument response before the fall.

4.1.5 Moisture exposure (rain and fog) testing shall be performed in accordance with ANSI

N42.17C-1989, Sections 8.12.2 and 8.13.2. An amount of 5 ± 1% of salt shall be added to the liquid to simulate salt spray exposure. The instrument will conform to the specification if the instrument response to a radiation source varies less than or equal to 15% during and after exposure to (1) lightly falling rain (one quarter of an inch per hour) for a period of 2 hours at 20 °C and (2) fog over a period of 6 hours at 22 °C.

4.1.6 Temperature shock testing shall be performed in accordance with ANSI N42.17A-2003, Section 9.2.2. The instrument will conform to the specification if the instrument's response when exposed to a temperature change from 22 °C to -10 °C, -10 °C to 22 °C, 22 °C to 50 °C, and 50 °C to 22 °C in less than five minutes is within 20% of the response at 22 °C. If the instrument does not meet these requirements, the manufacturer shall state the time required for the instrument to recover to within 20% of the reference reading. The recovery time shall be less than two hours. The test shall be performed on each user-selectable range.

4.1.7 EMI testing shall be performed in accordance with MIL-STD-461G.

Conducted Emissions (CE) 102: The instrument will conform to the specification if the electromagnetic emissions from the instrument do not exceed the specified requirements cited in MIL-STD-461G, Sections 3, 4, and 5 for power input leads, including returns.

CE 106: The instrument will conform to the specification if the CE appearing at the antenna port of the instrument do not exceed the specified requirements cited in MIL- STD-461G, Sections 3, 4, and 5.

Conducted Susceptibility (CS) 101: The instrument will conform to the specification if the instrument withstands signals coupled onto input power leads.

CS 114: The instrument will conform to the specification if the instrument withstands radio frequency signals coupled onto the instrument’s associated cabling.

CS 115: The instrument will conform to the specification if the instrument withstands impulse signals coupled onto the instrument’s associated cabling.

CS 116: The instrument will conform to the specification if the instrument withstands damped sinusoidal transients coupled onto the instrument’s associated cables and power leads.

CS 118: The instrument will conform to the specification if the instrument withstands personnel borne electrostatic discharge in a powered up configuration.

Radiated Emissions (RE) 102: The instrument will conform to the specification if the electric field emissions from the instrument and the instrument’s associated cabling do not exceed specified requirements.

RE 103: The instrument will conform to the specification if the radiated spurious and harmonic emissions from transmitters do not exceed the specified requirements cited in MIL-STD-416G, Sections 3, 4, and 5.

Radiated Susceptibility (RS) 101: The instrument will conform to the specification if the instrument is able to withstand radiated magnetic fields.

RS 103: The instrument will conform to the specification if the instrument and the instrument’s associated cabling is able to withstand electric fields.

RS 105: The instrument will conform to the specification if the instrument is able to withstand a transient electromagnetic field.

4.1.8 Fuel-air explosive atmosphere testing shall be performed in accordance with MIL-STD-

810H, Method 511.7, Section 4. The instrument will conform to the specification if the instrument operates in fuel-air explosive atmospheres without causing ignition in accordance with MIL-STD-810H, Method 511.7, Section 4, Procedure I.

4.2 Features

4.2.1 Dimensions shall be verified by examination. The instrument will conform to the specification if the dimensions of the instrument, and external probe (if applicable), do not exceed 5 in x 13 in x 10 in.

4.2.2 Weight shall be verified by examination. The instrument will conform to the specification if the weight of the instrument, and external probe (if applicable), does not exceed 7 pounds.

4.2.3 Minimum measurement range testing shall include at least two points on each range of 1μR/hr - 10μR/hr, 10 μR/hr - 200 μR/hr, 200 μR/hr- 400 μR/hr, 400 μR/hr – 600 μR/hr, 600 μR/hr – 800 μR/hr, 800 μR/hr – 1,000 μR/hr. The instrument will conform to the specification if the exposure rate is within ± 30% {±10%} accurate over the minimum measurement range of 1.0-1,000 μR/hr.

4.2.4 Units of the instrument shall be verified by demonstration. The instrument will conform to the specification if the minimum selectable measurement units are μR/hr or μrem/hr.

4.2.5 Minimum photon energy response range testing shall test approximately 80 keV, one point within the range of 100 keV – 500 keV, and the respective energy ranges for Cobalt-60, Americium-241, and Cesium-137.The instrument will conform to the specification if the responses are ± 20% {±10%} accurate for energies at and above 100 keV and -40% to +20% {10%} accurate for energies below 100 keV.

4.2.6 Warm-up testing shall be verified by demonstration. The instrument will conform to the specification if the instrument warm-up time does not exceed ten minutes {one minute}.

4.2.7 Absence of a cooling mechanism shall be verified by examination. The instrument will conform to the specification if the instrument does not have a cooling mechanism for detector function.

4.2.8 Absence of an attached source shall be verified by examination. The instrument will conform to the specification if the instrument does not have an attached source of radiation.

4.2.9 Battery power testing shall be performed in accordance with ANSI N42.17A-2003, Section 5.11.2. The instrument will conform to the specification if the instrument maintains battery power for at least 50 {100} hours under normal operating conditions, the batteries are commercially available, and the batteries are not lithium based.

4.2.10 Legibility of the display testing shall be performed in full sunlight (10+5) and in darkness (10-3) with the display light on. Under each of these conditions, readings shall be made of the display indications. The instrument will conform to the specification if the instrument display can be read from a distance of two feet {three feet}, with a maximum error of 10% (90% correct recognition of display) in an ambient light intensity of 10+5 lux (full sunlight) and 10-3 lux (darkness).

4.2.11 The general characteristics for health physics instrumentation shall be tested in accordance with ANSI N42.17A-2003, Section 5.

Scaling Factors: The instrument will conform to the specification if (1) the scaling factor between adjacent scales is a single integer multiple that does not exceed ten for an instrument on a linear scale, (2) there is a one decade overlap between adjacent scales for a logarithmic scale with switched measurement scales, or (3) the instrument indicates the scale and measurement units for each scale and a floating decimal point is displayed, if used.

Ease of Decontamination: The instrument will conform to the specification if the instrument is constructed to facilitate decontamination (e.g. a smooth, nonporous external surface free from crevices).

Markings: The instrument will conform to the specification if all external instrument controls, displays, and adjustments are identified as to function, and internal controls are identified through markings on circuit boards and identification in technical manuals.

Battery Status Indication: The instrument will conform to the specification if the instrument is equipped with a test circuit or other visible direct indicator of battery condition for each battery circuit.

Protection of Switches: The instrument will conform to the specification if the instrument's switches and other controls are protected to curb inadvertent deactivation or improper operation of the instrument.

Zero Set: The instrument will conform to the specification if the instrument adjusts to zero and the response is stable in the presence of radiation fields.

Battery Power: The instrument will conform to the specification if the manufacturer states the battery lifetime, battery-associated operating temperature requirements, and the minimum voltage required for satisfactory operation of the instrument in accordance with ANSI N42.17A-2003, Section 5.11.1. The battery lifetime shall be where the ratio of the mean reading relative to the mean reading taken after the warm-up period falls outside the interval 0.9 to 1.1. The minimum voltage shall be the voltage where there is a less than 10% change in instrument response compared to the response with fresh batteries.

Battery Power Indication: The instrument will conform to the specification if the mean instrument reading is within 10% of the mean reading obtained with fresh batteries when the low-battery indicator activates.

4.2.12 Surveying behind an obstacle shall be verified by demonstration. The instrument will conform to the specification if the instrument can obtain survey data behind obstacles in silent mode. If the instrument includes a control unit and an external probe, then the instrument will conform to the specification if the cable length is four feet to five feet. If the instrument has an embedded probe, then the instrument will conform to the specification if the dose rate readings acquired behind the obstacle are retrievable from the instrument.

4.2.13 Audible signals shall be verified by demonstration. The instrument will conform to the specification if the instrument operates with audible signals when exposed to radiation.

4.2.14 Silent mode shall be verified by demonstration. The instrument will conform to the specification if the instrument operates in silent mode.

4.2.15 Accuracy testing shall be performed on at least two points, at approximately 25% and 75%, within the response ranges of 1μR/hr - 10μR/hr, 10 μR/hr - 200 μR/hr, 200 μR/hr- 400 μR/hr, 400 μR/hr – 600 μR/hr, 600 μR/hr – 800 μR/hr, 800 μR/hr – 1,000 μR/hr. All tests shall be performed with the same isotope. For the 1μR/hr – 10 μR/hr range, an alternate method, such as an electronic pulse generator, may be used to extrapolate the response of the instrument to radioactive sources. If an alternate method is used, there shall be an overlap range of at least one decade between the alternate test data and the radiological test data to validate the conversion factor. The instrument will conform to the specification if each exposure rate meets the accuracy requirement of Section 3.2.15.

4.2.16 Angular dependence testing shall be performed in accordance with ANSI N42.17A-2003, Section 7.7.2 with Cobalt-60, Cesium-137, Americium-241, and 80 keV photon radiation.

The instrument will conform to the specification if (1) the instrument's response at any angle not exceeding 45 degrees from the direction of maximum response is not less than 80% of the maximum response and (2) the instrument's response at an angle of 90 degrees from the direction of maximum response is not less than 50% {80%} of the maximum response.

4.2.17 Stable response testing shall be performed as follows: The instrument shall be exposed in a low radiation environment of less than or equal to 10 μR/hr {3μR/hr}. Following warm-up, ten (10) successive readings shall be taken with the time interval between readings being equal to or greater than three (3) times the instrument response time.

The mean, standard deviation, and coefficient of variation of the instrument readings shall then be calculated. The instrument will conform to the specification if the coefficient of variation in a low radiation environment of less than or equal to coefficient of variation is the standard deviation divided by the mean.

4.2.18 Response time testing shall be performed as follows: Expose the instrument to an ambient radiation environment of less than or equal to 15 μR/hr {10 μR/hr}. Acquire at least 10 readings to determine the instrument’s mean reading (L2). Shield the instrument to a low radiation environment with a reduction in exposure rate of at least 5 μR/hr. After the instrument reading is allowed to stabilize in the low radiation environment, acquire at least 10 readings to determine the instrument’s mean reading (L1). Calculate the step change = L2 – L1. The response time shall be defined as the time for the instrument reading to go from L1 + *10% to L1 + *90%, when the exposure rate changes quickly from the low radiation environment to the ambient radiation environment (rising response time), or from L1 + *90% to L1 + *10% when the exposure rate changes quickly from the ambient radiation environment to the low radiation environment (falling response time). These two measurements shall be repeated at least 10 times each. The instrument will conform to the requirement if the response time (rising or falling) does not exceed 20 seconds in any trial or if the mean response time (rising or falling) for all trials does not exceed 15 seconds.

4.2.19 Not subtracting any ionizing radiation signals shall be verified by examination of the software source code. The instrument will conform to the specification if the software source code for the instrument was written to not subtract any ionizing radiation signals within the minimum photon energy response range, including signals from natural background radiation sources. If a software source code is unavailable, then not subtracting any ionizing radiation signals shall be verified by testing. The detector shall be exposed in an area of known (conventionally true value determined) background radiation. After allowing time for the instrument reading to stabilize (based on manufacturer recommendation), read the instrument display and note 10 separate readings with approximately 10 seconds between readings. Determine the average of the 10 readings. The instrument will conform to the specification if the average of the 10 readings is at least 50% of the conventionally true background rate. The method for determining the conventionally true background level will be specified by the testing facility.

4.2.20 Scaler function shall be verified by demonstration. The instrument will conform to the specification if the user is able to configure a preset time mode, preset count mode, and gross counting mode and receive an indication of an overflow condition. {The instrument will conform to the specification if the user is able to configure energy/pulse height window counting mode and gross counting mode.}

5. Packaging

5.1 The instrument shall be delivered in a hard-shell carrying case with a Cross-Linked

Polyethylene (XLPE) foam insert to support and protect the equipment. Name plates shall also be placed on the outside of the carrying case in accordance with MIL-DTL- 15024G. The Government shall approve of the design and placement of name plates on the carrying case before delivery of the instruments.

6. Notes

This section is not applicable to this specification.