Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.naic.edu/~phil/hardware/rfmonitor/Smarts09UsersGuid.pdf Äàòà èçìåíåíèÿ: Fri Jun 29 21:34:43 2012 Äàòà èíäåêñèðîâàíèÿ: Mon Feb 4 21:12:39 2013 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ôëóîðåñöåíöèÿ

SMARTS II

TM

ULTRA-WIDEBAND RF RADIATION AREA MONITORS

USER 'S GUIDE

narda
Safety Test Solutions
an

L3

communications company

P/N 42995800


narda
Safety Test Solutions
an

L3

communications company

© 2009 L-3 Communications Printed in the U.S.A.

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Table of Contents

CHAPTER 1 INTRODUCTION ................................................5 About Your SMARTS II ..............................................5 Equipment Supplied ..................................................5 Optional Equipment ..................................................6 CHAPTER 2 U
NDERSTANDING

YOUR SMARTS II ....................7

General Description ..................................................7 Models ......................................................................8 Specifications ............................................................9 Test Switch ..............................................................10 Audio Alarm ............................................................10 LED Indicator ..........................................................11 Sensor......................................................................11 Battery Compartment ..............................................11 Input/Output Connector ..........................................12 Outline Drawing ......................................................12 CHAPTER 3 INDOOR INSTALLATION ....................................13 Location ..................................................................13 Options ....................................................................13 Mounting the SMARTS II Indoors............................13 Basic Battery Operation ..........................................14 Operation with an External Power Supply ..............15 Alarm Threshold Adjustment ..................................16 Zeroing Procedure ..................................................17

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Test Switch ..............................................................17 Remote Alarm Indication ........................................17 Using the ENABLE Feature ....................................18 Remote Test ............................................................19 Low Battery Indication ............................................19 CHAPTER 4 OUTDOOR INSTALLATIONS ..............................21 Location ..................................................................21 Options ....................................................................21 Using the SMARTS II Outdoors ..............................22 Alarm Threshold Adjustment ..................................24 Remote Alarm Indication ........................................24 Using the ENABLE Feature ....................................25 Remote Test ............................................................26 C
HAPTER

5 MAINTENANCE ..............................................27

General ....................................................................27 Calibration ..............................................................27 Battery Replacement ..............................................27 Battery Life According to Type ................................28 CHAPTER 6 D
ETERMINING

LOCATION ................................29

Overview ..................................................................29 Factors Determining Area Coverage ......................30 Preferred Location ..................................................30 Alternate Locations ..................................................31 WARRANTY ......................................................................32 INDEX ..............................................................................33 A
BOUT

NARDA S

AFETY

TEST SOLUTIONS ..........................34

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Chapter 1 INTRODUCTION About Your SMARTS IITM
The SMARTS II is the latest design in the SMARTSTM family of RF area monitors. They provide continuous detection of RF radiation within a specific area. The SMARTS II uses the latest, ultra-broadband sensor technology developed for Narda Safety Test Solutions' NardalertTM RF personal monitors.

Equipment Supplied
The SMARTS II is supplied with: o SMARTS II area monitor o Mating 9-pin connector, P/N 42995900 o Battery, 9 Volt Lithium P/N 88020000 o User 's Guide, P/N 42995800

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Optional Equipment
The following optional accessories are available for use with the SMARTS II: o Weatherproof Housing, P/N 11081900 o Mounting Adapter Kit, P/N 42993200 The weatherproof housing should be used whenever the SMARTS II is to be installed in an area exposed to precipitation.

The mounting adapter kit is used only when it is important for the SMARTS II to use the same mounting-hole pattern as the original SMARTS area monitors.

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Chapter 2

UNDERSTANDING YOUR SMARTS II
General Description
The SMARTS IITM area monitors, like earlier SMARTS models, provide continuous detection of RF radiation within a specific area. The SMARTS II uses the latest, ultra-wideband sensor technology of the NardalertTM RF personal monitors. The result is an area monitor that covers most of the usable RF spectrum in a single monitor with "shaped" frequency-dependent sensitivity that matches the standard used to determine compliance. The dual sensor design accurately detects all types of electric fields from 2 MHz to 100 GHz. The microwave portion of the sensor employs thermocouple detectors so that radar signals are accurately converted to true RMS values while the patented diode design used for the lower frequencies provides RMS detection even in very complex, multi-signal environments. SMARTS II monitors respond equally to all polarizations and cover an entire hemisphere. The SMARTS II operates from a common nine-volt battery or an external 12-volt or 24-volt DC supply. Every monitor has an audio alarm. An alarm condition causes a voltage transition (TTL) to occur at the STATUS jack. When the SMARTS II is operated from an external power supply, you have the option to use the contacts of an SPDT (Single Pole Double Through) relay to indicate alarm status. The status relay cannot be used under battery operation. Either the TTL signal or the relay contacts can be used to provide remote alarms, a record of alarm conditions, and/or automatic shutoff of equipment.

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Models
SMARTS II area monitors cover most of the usable RF spectrum in a single monitor with "shaped" frequency-dependent sensitivity that matches the standard used to determine compliance. The "shape" of the frequency response is the only difference between the four SMARTS II models. Standard or Guidance ACGIH AS/NZ 2772.1 (1998, draft) Canada Safety Code 6 99-EHD-237 DIN VDE 0848, Part 2, October 1991 Area 1 ENV 50166-2 FCC 1997 ICNIRP 1998 IEEE C95.1-1999 & ANSI C95.1-1992 Japan RCR-38 NATO STANAG 2345 æNORMS S 1120, 1992 Tier -- Occupational RF Workers Occupational Occupational Occupational / Controlled Occupational Controlled Controlled -- Occupational Model B8830 D8830 C8830 D8830 D8830 A8830 D8830 B8830 A8830 B8830 A8830

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Specifications
Parameter
Frequency Range
a

Specification
2 MHz to 100 GHz +6.0 +4.5 +2.5 +2.5 / / / / -3.0 -2.5 -6.0 -6.0 dB dB dB dB (2 MHz to 2.3 GHz) (2.3 to 30 GHz) (30 to 50 GHz) (50 to 100 GHz, Typ.)

Frequency Sensitivity

Calibration Frequencies Alarm Threshold Maximum CW Power Density Maximum Peak Power Density Battery External Power Requirements STATUS Signal Levels Load Impedance, min. Status Relay Type Power Rating Recorder Output Level Load Impedance, min Temperature Operating Non-operating Size, approximate Weight, approximate Color
a

100 MHz, 4 GHz 10%, 25%, 35%, or 50% of Standard 3000% of Standard 32 dB above Standard 9 volt alkaline 12 Vdc ±10%, 50 ma max/ 24 Vdc ±10%, 50 ma max -4 Vdc standby, +4 Vdc alarm 100 k SPDT Reed Relay 3W @ 250 mA, 28 Vdc 1 Vdc full scale (approximate) 100 k -10°C to +55°C -20°C to +65°C 9.4" L x 8.1" W x 5.0" H 23.9 cm x 20.6 cm x 12.7 cm 26 oz / 0.74 kg White

Accuracy specified as the mean of the radial and ver tical orientations (10 to 1600 MHz) and mean of the ver tical and horizontal orientations (1600 MHz to 50 GHz).

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Specifications for the optional weatherproof housing are shown in the table below. Parameter Part Number Construction Frequency Range Rating Size Weight, approximate Color Specification 11081900 All plastic See Note a NEMA class 4X
b

11.8" L x 11.8" W x 7.2" H 30.0 cm x 30.0 cm x 18.3 cm 45 oz/6.2 kg 45 oz/6.2 kg

Notes: a. The insertion loss of the housing is insignificant below 5 GHz but can be as high as 2 dB at higher frequencies (no data is available above 40 GHz). Under rain conditions an additional insertion loss from a water film on the housing can be up to 10 dB at frequencies above 5 GHz. b. Equivalent to IEC Publication 529, Type IP 66 or CSA Standard C22.2, No. 94.

Test Switch
The TEST switch provides a means to test most of the monitor circuitry. Momentarily pressing TEST simulates an alarm condition.

Audio Alarm
The audio alarm is sufficiently loud for most indoor applications. An external alarm, audio and/or visual, is recommended when the SMARTS II is located in an area with significant ambient noise or when it is mounted inside the weatherproof housing.

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LED Indicator
The red LED indicator flashes approximately every forty seconds whenever the SMARTS II is functioning normally.

Sensor
The SMARTS II accurately detects all types of electric fields from 2 MHz to 100 GHz. The monitor uses three sets of sensors. The microwave portion of each sensor employs thermocouple detectors so that radar signals are accurately converted to true RMS values while the patented diode design used for the lower frequencies provides RMS detection even in very complex, multi-signal environments. The output of the three high frequency sensors is combined and fed to a low-noise amplifier circuit. Similarly, the output of the three low frequency sensors is combined and fed to another low-noise amplifier. The output of these two amplifier circuits is calibrated in terms of Percent of Standard. The sum of these two amplifier levels is used to determine whether the monitor is above or below the alarm threshold that has been selected by the user. SMARTS II monitors respond equally to all polarizations and cover an entire hemisphere.

Battery Compartment
Removing a cover that is attached with four captive screws accesses the battery compartment. The cover has an RFI (Radio Frequency Interference) gasket to ensure that the internal circuits remain isolated from strong electromagnetic fields. A standard 9-volt alkaline battery is located within the battery compartment. The BATT­PS (battery­power supply) switch and a two-section Alarm Threshold DIP switch are also located within the battery compartment.

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Input/Output Connector
All input and output connections are made via a single, 9-pin Dsubminiature male connector located on the side of the SMARTS II. A mating connector is supplied with the monitor. This input/output connector is used to provide connections for: o Relay contacts (N.C., COM., and N.O.) o ENABLE/RECORDER o STATUS (TTL level) o External 12 Vdc or 24 Vdc power The internal cable of the weatherproof housing plugs into this connector. This input/output connector is filtered to protect the SMARTS II from strong electromagnetic fields. However, a shielded cable is highly recommended.

Outline Drawing

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Chapter 3

INDOOR INSTALLATION
Location
The location where you mount the SMARTS II depends on many factors. See Chapter 6, Determining Location for an explanation and recommendations.

Options
It is important to decide how the SMARTS II will be used before you mount it. It is far easier to change settings and make connections with the monitor in front of you rather than after it is mounted. The important decisions involve: o Power Source ­ either the internal battery or an external 12 Vdc or 24 Vdc power supply can power the monitor. o Alarm Threshold ­ the default setting is 50% of Standard. Three more sensitive settings are available. o Alarm Indications ­ either the internal audio alarm and/or a remote indication can be used. External alarms require a cable connection. o Remote Test ­ available with a cable connection. o Enable ­ alarm operation can be inhibited when people are not present during high power operation.

Mounting the SMARTS II Indoors
The basic SMARTS II (without weatherproof housing) is attached to any surface with two screws. The type and size of the screws are determined by the mounting surface. The SMARTS II can be attached to any surface, even conductive metal surfaces.

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Basic Battery Operation
The SMARTS II can be used in its basic form by operating from the internal 9-volt battery and the built-in audio alarm. No external connections are required. To operate the SMARTS II from a battery without external connections... 1. Remove the battery-compartment door by loosening the four captive screws. 2. Connect the battery. The monitor is shipped with the battery supplied in a separate package to maintain battery life while in storage and during shipment. 3. Move the BATT­PS switch (battery­power supply), which is located inside the battery compartment, to the BATT position.
INSIDE BATTERY COMPARTMENT
S2 BATT

TP1 S4

ALARM THRESHOLD SWITCH
S3 ON

REV

CONNECTOR REMOVE FOR EXTERNAL POWER INSTALLATIONS

4. Set the alarm threshold to the desired level. See Alarm Threshold Adjustment. 5. Replace the battery-compartment cover and finger-tighten the four captive screws. 6. Mount the monitor in the desired location using the holes in the mounting brackets and screws suitable for the surface that the monitor is being mounted on.

1 PS

BATT-PS SWITCH

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Operation with an External Power Supply
The SMARTS II can be operated from an external low voltage supply. It can also be connected to an external circuit to make use of its remote-alarm capability by using the same cable and connector used for the power supply. To operate the SMARTS II from an external low voltage supply... 1. Remove the battery-compartment door by loosening the four captive screws. 2. Remove the battery if it has previously been installed. The monitor is shipped with the battery supplied in a separate package to maintain battery life while in storage and during shipment.

3. Check to make sure that the BATT­PS switch (batterypower supply), which is located inside the battery compartment, is set to the PS position. 4. Set the alarm threshold to the desired level. See Alarm Threshold Adjustment. 5. Insure that the battery connector is not touching a metal surface. Alternately, the battery connector and leads make be removed by simply disconnecting at the printed circuit board. 6. Replace the battery-compartment cover and finger-tighten the four captive screws. 7. Connect the SMARTS II to either a 12 VDC or 24 VDC external power supply. It is critical that the power supply be a "floating" one.

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8. Mount the monitor in the desired location using the holes in the mounting brackets and screws suitable for the surface that the monitor is being mounted on. oooNOTEooo Use shielded cable to make connections to the input/output connector.

Alarm Threshold Adjustment
The alarm threshold can be set to any one of four values: 10%, 25%, 35%, or 50% of Standard. The default setting is 50% of Standard. To change the alarm threshold... 1. Loosen the four captive screws and remove the battery compartment cover. 2. Adjust the two-section DIP-switch located inside the battery compartment to set the alarm threshold to the desired level. Use the diagram on the inside of the battery compartment cover to determine the correct setting for each section.
INSIDE BATTERY COMPARTMENT
S2 BATT

TP1 S4

ALARM THRESHOLD SWITCH
S3 ON

REV

CONNECTOR REMOVE FOR EXTERNAL POWER INSTALLATIONS

3. Replace the battery compartment cover.

1 PS

BATT-PS SWITCH

INSIDE BATTERY COVER

S4

ALARM THRESHOLD 10% 25% 35% 50%

S3 OFF OFF ON ON

S4 OFF ON OFF ON

S3

ON

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It is recommended that if the SMARTS II is to be operated with a power supply, the Zero setting should be checked, and adjusted if necessary. The Zero voltage is checked by measuring the voltage between Pins 2 (ENABLE/RECORDER) and 9 (GND) of the 9-pin D-subminiature connector.

Zeroing Procedure
Connect power supply. Select threshold range (see Alarm Threshold Adjustment, above). Remove plate adjacent to test button, with two phillips head screws (see outline drawing, page 12). Adjust the middle potentiometer for 0.00 Vdc (± 10 mV) while monitoring between Pins 2 and 9 of the 9-pin D-subminiature connector, or Pins P and C of the 15-pin connector (when mounted in P/N 11081900, Outdoor Enclosure). This adjustment will not affect calibration, as long as it is performed correctly. Re-attach plate after performing adjustment.

Test Switch
The TEST switch provides a means to test most of the monitor circuitry. Momentarily pressing TEST simulates an alarm condition.

Remote Alarm Indication
Alarm status can be detected remotely by using the STATUS signal, the RECORDER output level, and/or the STATUS relay (Form C or SPDT) connections. The relay cannot be used under battery operation. oooCAUTIONooo Do Not Exceed Relay Contact Rating of 3W@ 250 mA, 28 Vdc

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o The level on the STATUS line transitions from -4 Vdc under standby conditions to a +4 Vdc under alarm conditions. o The ENABLE/RECORDER line serves a dual function. When used to monitor field strength, the Recorder Output Level varies from 0 Vdc to ­1 Vdc. Full scale represents the level at which the SMARTS II is set to sound its alarm. For example, if the Alarm Threshold is set to 50% of standard, a ­0.5 Vdc level indicates that the field strength is approximately 25% of standard. o The SPDT STATUS relay operates whenever there is an alarm condition. Under alarm conditions, there is a connection between the common (COM) terminal and the normally open (N.O.) terminal.

Using the ENABLE Feature
The ENABLE input can be used in situations where the standard operating procedure produces RF fields above the alarm threshold and exposure to people is possible. Examples include an anechoic chamber and the deck of a ship. The ENABLE input can be tied to a motion sensor or an interlock switch. Under these conditions, the SMARTS II activates its alarms only when two conditions are satisfied: o High levels of RF are present (above the monitors alarm threshold). o Motion is detected or a door is open. To use the ENABLE feature... o To inhibit the SMARTS II alarm function under certain conditions connect a switch or relay between the ENABLE line and the monitor 's ground: Pins 2 (ENABLE/RECORDER) and 9 (GND) on the Input/Output Connector.
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o The SMARTS II will function normally whenever the relay contacts or the switch is open. o The SMARTS II alarm function will not function whenever the relay contacts or the switch is closed.

Remote Test
It is possible to test the SMARTS II from a remote location when it is not practical to reach the TEST switch. To test the SMARTS II alarm function... 1. Momentarily ground the STATUS line. The monitor go into alarm status. This is best accomplished by necting a cable to the 9-pin Input/Output connector. test is made by connecting pin 4 (STATUS) to pin 9 For Relay activation... 1. Connect Pin 4 (STATUS) through the switch and a 10 k ohm resistor (12 Vdc operation), or through the switch and a 100 k ohm resistor (24 Vdc operation). This will test the system and cause the relay to change position. should conThe (GND).

Low Battery Indication
The SMARTS II indicates a low battery situation by "chirping" its alarm. The alarm will sound in approximately forty-second intervals whenever the battery level is low. The battery should be replaced as soon as possible.

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Chapter 4

OUTDOOR INSTALLATIONS
Location
Where you mount the SMARTS II depends on many factors. See Chapter 6, Determining Location, for an explanation and recommendations.

Options
It is important to decide how the SMARTS II will be used before you mount it. It is far easier to change settings and make connections with the monitor in front of you rather than after it is mounted. The important decisions involve: o Power Source ­ either a 12 Vdc or 24 Vdc external power supply can power the monitor. Battery operation is not recommended for monitors mounted inside the weatherproof housing. o Alarm Threshold ­ the default setting is 50% of Standard. Three more sensitive settings are available. o Alarm Indications ­ there are three different remote alarm options. The internal audio alarm is not a practical option for monitors mounted inside the weatherproof housing. o Remote Test ­ available via the same cable used to supply power and remote alarm signals. o Enable ­ alarm operation can be inhibited when people are not present during high power operation.

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Using the SMARTS II Outdoors
The SMARTS II can be used outdoors, even in severe weather, when installed in the optional Weatherproof Housing, P/N 11081900. To install the SMARTS II inside the optional weatherproof housing and to mount the entire assembly... 1. Remove the battery-compartment door by loosening the four captive screws.

2. Remove the battery if it has previously been installed. The monitor is shipped with the battery supplied in a separate package to maintain battery life while in storage and during shipment. 3. Check to make sure that the BATT­PS switch (batterypower supply), which is located inside the battery compartment, is set to the PS position 4. Set the alarm threshold to the desired level. See Alarm Threshold Adjustment.
INSIDE BATTERY COMPARTMENT
S2 BATT

TP1 S4

ALARM THRESHOLD SWITCH
S3 ON

REV

CONNECTOR REMOVE FOR EXTERNAL POWER INSTALLATIONS

4. Set the alarm threshold to the desired level. 5. Insure that the battery connector is not touching a metal surface. Alternately, the battery connector and leads may be removed by simply disconnecting at the printed circuit board.

1 PS

BATT-PS SWITCH

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6. Replace the battery-compartment cover and finger-tighten the four captive screws. 7. Remove the cover of the weatherproof housing. 8. Remove the two screws from inside the weatherproof housing. 9. Plug the cable attached to the weatherproof housing into the 9-pin subminiature D connector on the SMARTS II. 10. Attach the SMARTS II to the weatherproof housing using the same two screws and the same mounting holes. 11. With the housing surface. corners SMARTS II now attached, mount the weatherproof to any surface using four screws suitable for the These screws install in the four large holes in the of the housing used to attach the cover

12. Replace the cover of the weatherproof housing.

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Alarm Threshold Adjustment
The alarm threshold can be set to any one of four values: 10%, 25%, 35%, or 50% of Standard. The default setting is 50% of Standard. To change the alarm threshold... 1. Loosen the four captive screws and remove the battery compartment cover. 2. Adjust the two-section DIP-switch located inside the battery compartment to set the alarm threshold to the desired level. Use the diagram on the inside of the battery compartment cover to determine the correct setting for each section.
INSIDE BATTERY COMPARTMENT
S2 BATT

TP1 S4

ALARM THRESHOLD SWITCH
S3 ON

REV

CONNECTOR REMOVE FOR EXTERNAL POWER INSTALLATIONS

3. Replace the battery compartment cover.

Remote Alarm Indication
The internal audio alarm is of little value when the SMARTS II is mounted inside the weatherproof housing. Alarm status can be detected remotely by using the STATUS signal, the RECORDER output level, and/or the STATUS relay (Form C or SPDT) connections.

1 PS

BATT-PS SWITCH

INSIDE BATTERY COVER

S4

ALARM THRESHOLD 10% 25% 35%

S3 OFF OFF ON ON

S4 OFF ON OFF ON

S3

ON

50%

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oooCAUTIONooo Do Not Exceed Relay Contact Rating of 3W@ 250 mA, 28 Vdc

o The level on the STATUS line transitions from a ­4 Vdc under standby conditions to a +4 Vdc under alarm conditions. o The ENABLE/RECORDER line serves a dual function. When used to monitor field strength, the Recorder Output Level varies from 0 Vdc to ­1 Vdc. Full scale represents the level at which the SMARTS II is set to sound its alarm. For example, if the Alarm Threshold is set to 50% of standard, a ­0.5 Vdc level indicates that the field strength is approximately 25% of standard. o The SPDT STATUS relay operates whenever there is an alarm condition. Under alarm conditions, there is a connection between the common (COM) terminal and the normally open (N.O.) terminal.

Using the ENABLE Feature
The ENABLE input can be used in situations where the standard operating procedure produces RF fields above the alarm threshold and exposure to people is possible. Examples include an anechoic chamber and the deck of a ship. The ENABLE input can be tied to a motion sensor of an interlock switch. Under these conditions, the SMARTS II activates its alarms only when two conditions are satisfied: o High levels of RF are present (above the monitors alarm threshold). o Motion is detected or a door is open. To use the ENABLE feature... 1. To inhibit the SMARTS II alarm function under certain conditions connect a switch or relay between the ENABLE line and the monitor 's ground: Pins 2 (ENABLE/RECORDER) and 9 (GND) on the Input/Output Connector.
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2. The SMARTS II will function normally whenever the relay contacts or the switch is open. 3. The SMARTS II alarm function will not function whenever the relay contacts or the switch is closed.

Remote Test
It is possible to test the SMARTS II from a remote location when it is not practical to reach the TEST switch. To test the SMARTS II alarm function... Momentarily ground the STATUS line. The monitor should go into alarm status. This is best accomplished by connecting a cable to the 15-pin MIL style Input/Output connector located on the weatherproof housing. The test is made by connecting pin E (STATUS) to pin P (GND). For Relay activation... Connect Pin E through external switch and 10 k ohm resistor, to Pin A (12 Vdc operation), or connect switch and 100 k ohm resistor, to Pin B (24 Vdc operation).

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Chapter 5 MAINTENANCE General
SMARTS II area monitors require very little maintenance. No operator adjustments are required other than the initial selection of Alarm Threshold. The plastic housing may be cleaned using a damp cloth. Do not use any type of detergent or solvent.

Calibration
SMARTS II monitors are calibrated before shipment. Narda Safety Test Solutions recommends that the x8830 series SMARTS II monitors be calibrated every two years. Narda will perform this calibration for a nominal charge.

Battery Replacement
The SMARTS II indicates a low battery situation by "chirping" its alarm. The alarm will sound in approximately forty-second intervals whenever the battery level is low. The battery should be changed as soon as possible once the low battery condition is indicated.

To change the battery... 1. Loosen the four captive screws that hold the battery compartment cover. The screw heads are knurled and should only be finger tight but a slot is provided for a screwdriver should it be needed.

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2. Remove the cover. 3. Disconnect the battery leads, replace the battery, and connect the leads. 4. Put the battery into the compartment and replace the cover. 5. Tighten all four screws. It is important that the screws are tightened sufficiently so that the cover slightly compresses the EMI gasket.

Battery Life According to Type
The SMARTS II is shipped with a 9-volt lithium battery. It should operate for approximately 6-8 months before it must be changed. A standard 9-volt alkaline battery will power the SMARTS II for approximately 3-4 months. Alkaline batteries are available from numerous companies and retail stores. Lithium batteries are usually available wherever cameras and camera supplies are sold. The lithium battery supplied with the monitor is Ultralife Batteries P/N U9VL.

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Chapter 6

DETERMINING LOCATION
Overview
The factors that determine when a SMARTS II monitor will activate its alarms include: o Alarm Threshold setting of the monitor o The field strength at the monitor in terms of Percent of Standard. The alarm threshold is set at the factory at 50% of standard. Three more sensitive settings available: 35%, 25%, and 10% of standard. The actual field strength required for the monitor to activate its alarms depends not only on the alarm threshold setting but the field strength of each frequency component. The sensitivity of SMARTS II area monitors varies with the specific model. All four models have shaped frequency response. For example, model D8830 follows the ICNIRP occupational limits. The ICNIRP occupational limits are 1 mW/cm2 from 10 MHz to 400 MHz and 5 mW/cm2 above 2 GHz. If the SMARTS II were set to the least sensitive setting of 50% of standard, then the threshold (excluding tolerances) would be 0.5 mW/cm2 in the VHF region and 2.5 mW/cm2 in the microwave region. The "weighting" of the frequency response of the sensors automatically compensates for multiple signal environments. Area coverage is a far more complicated subject. There are several factors that should be considered in determining the best location for the monitor and the area that can be considered "protected."

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Factors Determining Area Coverage
Energy sources, either purposeful emitters such as antennas, or unintentional emitters such as waveguide leaks, can be omnidirectional or focused in one direction. Field strength (power density expressed in mW/cm2 or W/m2) drops off rapidly with distance from the source. In the far field, field strength follows the inverse square law, i.e., at twice the distance there is one quarter the field strength. Similarly, at ten times the distance, the field strength is only one percent as strong. Factors influencing area coverage include: o Location of the SMARTS II o Location of the energy source o Location of people o Energy level of the source. o Direction of energy being emitted o Orientation of the SMARTS II

Preferred Location
The ideal location for a SMARTS II is between the source of energy and people. The SMARTS II should be "pointed" at the energy source. Under these conditions the sensitivity of the monitor is never an issue because it will always detect a higher field level than the people are exposed to. Since the SMARTS I