Test report

FCC ID: NMTTHR128-01

Test Report

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FCCID_14174

IDT Technology Ltd. Application For Class II Permissive Change (FCC ID: NMTTHR128-01) Transmitter WO# 9807315 CKL/at November 24, 1998 • The test results reported in this report shall refer only to the sample actually tested and shall not refer or be deemed to refer to bulk from which such a sample may be said to have been obtained. • This report shall not be reproduced except in full without prior authorization from Intertek Testing Services Hong Kong Limited FCC ID : NMTTHR128-01

INTERTEK TESTING SERVICES LIST OF EXHIBITS INTRODUCTION EXHIBIT 1: General Description EXHIBIT 2: System Test Configuration EXHIBIT 3: Emission Results EXHIBIT 4: Equipment Photographs EXHIBIT 5: Product Labelling EXHIBIT 6: Technical Specifications EXHIBIT 7: Instruction Manual EXHIBIT 8: Miscellaneous Information FCC ID: NMTTHR128-01 i

INTERTEK TESTING SERVICES MEASUREMENT/TECHNICAL REPORT IDT Technology Ltd. - MODEL: CABLE FREE THERMO SENSOR THR128 FCC ID: NMTTHR128-01 November 24, 1998 This report concerns (check one:) Original Grant Class II Change X Equipment Type: Low Power Transmitter (example: computer, printer, modem, etc.) Deferred grant requested per 47 CFR 0.457(d)(1)(ii)? Yes No X If yes, defer until: date Company Name agrees to notify the Commission by: date of the intended date of announcement of the product so that the grant can be issued on that date. Transition Rules Request per 15.37? Yes No X If no, assumed Part 15, Subpart C for intentional radiator - the new 47 CFR [10-1-96 Edition] provision. Report prepared by: C. K. Lam Intertek Testing Services 2/F., Garment Center, 576, Castle Peak Road, HONG KONG Phone: 852-2746-8218 Fax: 852-2785-5487 FCC ID: NMTTHR128-01 ii

INTERTEK TESTING SERVICES Table of Contents 1.0 General Description ................................................................................................................. 2 1.1 Product Description ............................................................................................................. 2 1.2 Related Submittal(s) Grants ................................................................................................. 2 1.3 Test Methodology ................................................................................................................ 3 1.4 Test Facility ......................................................................................................................... 3 2.0 System Test Configuration ...................................................................................................... 5 2.1 Justification.......................................................................................................................... 5 2.2 EUT Exercising Software .................................................................................................... 5 2.3 Special Accessories.............................................................................................................. 5 2.4 Equipment Modification ...................................................................................................... 6 2.5 Support Equipment List and Description.............................................................................. 6 3.0 Emission Results ...................................................................................................................... 8 3.1 Field Strength Calculation.................................................................................................... 9 3.1 Field Strength Calculation (cont) ....................................................................................... 10 3.2 Radiated Emission Configuration Photograph.................................................................... 11 3.3 Radiated Emission Data ..................................................................................................... 12 4.0 Equipment Photographs........................................................................................................ 16 5.0 Product Labelling .................................................................................................................. 18 6.0 Technical Specifications ........................................................................................................ 20 7.0 Instruction Manual ................................................................................................................ 22 8.0 Miscellaneous Information.................................................................................................... 24 8.1 Measured Bandwidth ......................................................................................................... 25 8.2 Discussion of Pulse Desensitization................................................................................... 26 8.3 Calculation of Average Factor............................................................................................ 27 8.4 Emissions Test Procedures................................................................................................. 28 8.4 Emissions Test Procedures (cont'd).................................................................................... 29 FCC ID: NMTTHR128-01 iii

INTERTEK TESTING SERVICES List of attached file Exhibit type Filename Test Report report.doc Test Setup Photo radiated.jpg External Photo ophoto1.jpg & ophoto2.jpg Internal Photo iphoto1.jpg to iphoto4.jpg Block Diagram block.pdf Schematics circuit.pdf ID Label/Location label.pdf User Manual manual.pdf Test Report af.pdf, tx-time.pdf Test Report bw.pdf Cover Letter lettter.pdf Operational Description descri.pdf, change.pdf FCC ID: NMTTHR128-01 iv

INTERTEK TESTING SERVICES EXHIBIT 1 GENERAL DESCRIPTION FCC ID: NMTTHR128-01 1

INTERTEK TESTING SERVICES 1.0 General Description 1.1 Product Description The Equipment Under Test (EUT) is a transmitter portion of a wireless thermometer system operating at 433.92 MHz which is controlled by a crystal. The EUT is powered by two “AAA” size batteries. There are two switches (channel selector and temperature selector °C/°F) and a reset button inside the battery compartment. During normal use, it transmits temperature signal for 375 ms to receiver every 30 seconds. Each receiver can be used associated with three transmitters. For electronic filing, the brief circuit description and change description are saved with filename: descri.pdf, and change.pdf respectively.. 1.2 Related Submittal(s) Grants This is a single application for certification of a transmitter. The FCC ID of the receiver associated with this transmitter is NMTEMR899-01 which is granted on Dec. 3, 1997. FCC ID: NMTTHR128-01 2

INTERTEK TESTING SERVICES 1.3 Test Methodology Radiated emission measurements were performed according to the procedures in ANSI C63.4 (1992). All measurements were performed in Open Area Test Sites. Preliminary scans were performed in the Open Area Test Sites only to determine worst case modes. For each scan, the procedure for maximizing emissions in Appendices D and E were followed. All Radiated tests were performed at an antenna to EUT distance of 3 meters, unless stated otherwise in the "Justification Section" of this Application. 1.4 Test Facility The open area test site and conducted measurement facility used to collect the emission data is located at Garment Centre, 576 Castle Peak Road, Kowloon, Hong Kong. This test facility and site measurement data have been fully placed on file with the FCC. FCC ID: NMTTHR128-01 3

INTERTEK TESTING SERVICES EXHIBIT 2 SYSTEM TEST CONFIGURATION FCC ID: NMTTHR128-01 4

INTERTEK TESTING SERVICES 2.0 System Test Configuration 2.1 Justification The equipment under test (EUT) was configured for testing in a typical fashion (as a customer would normally use it). The EUT was mounted to a cardboard box, which enabled the engineer to maximize emissions through its placement in the three orthogonal axes. The worst case bit sequence was applied during test. The EUT was powered from two new "AAA" size batteries. For maximizing emissions, the EUT was rotated through 360°, the antenna height was varied from 1 meter to 4 meters above the ground plane, and the antenna polarization was changed. This step by step procedure for maximizing emissions led to the data reported in Exhibit 3.0. The unit was operated standalone and placed in the center of the turntable. For simplicity of testing, the unit was wired to transmit continuously. 2.2 EUT Exercising Software There was no special software to exercise the device. Once the button is depressed, the unit transmits the typical signal. For simplicity of testing, the unit was wired to transmit continuously. 2.3 Special Accessories There are no special accessories necessary for compliance of this product. FCC ID: NMTTHR128-01 5

INTERTEK TESTING SERVICES 2.4 Equipment Modification Any modifications installed previous to testing by IDT Technology Ltd. will be incorporated in each production model sold/leased in the United States. No modifications were installed by Intertek Testing Services. 2.5 Support Equipment List and Description This product was tested in a standalone configuration. All the items listed under section 2.0 of this report are Confirmed by: C. K. Lam Assistant Manager Intertek Testing Services Agent for IDT Technology Ltd. _ Signature November 24, 1998 Date FCC ID: NMTTHR128-01 6

INTERTEK TESTING SERVICES EXHIBIT 3 EMISSION RESULTS FCC ID: NMTTHR128-01 7

INTERTEK TESTING SERVICES 3.0 Emission Results Data is included worst case configuration (the configuration which resulted in the highest emission levels). A sample calculation, configuration photographs and data tables of the emissions are included. FCC ID: NMTTHR128-01 8

INTERTEK TESTING SERVICES 3.1 Field Strength Calculation The field strength is calculated by adding the reading on the Spectrum Analyzer to the factors associated with preamplifiers (if any), antennas, cables, pulse desensitization and average factors (when specified limit is in average and measurements are made with peak detectors). A sample calculation is included below. FS = RA + AF + CF - AG + PD + AV where FS = Field Strength in dBµV/m RA = Receiver Amplitude (including preamplifier) in dBµV CF = Cable Attenuation Factor in dB AF = Antenna Factor in dB AG = Amplifier Gain in dB PD = Pulse Desensitization in dB AV = Average Factor in -dB In the radiated emission table which follows, the reading shown on the data table may reflect the preamplifier gain. An example of the calculations, where the reading does not reflect the preamplifier gain, follows: FS = RA + AF + CF - AG + PD + AV FCC ID: NMTTHR128-01 9

INTERTEK TESTING SERVICES 3.1 Field Strength Calculation (cont) Example Assume a receiver reading of 62.0 dBµV is obtained. The antenna factor of 7.4 dB and cable factor of 1.6 dB is added. The amplifier gain of 29 dB is subtracted. The pulse desensitization factor of the spectrum analyzer was 0 dB, and the resultant average factor was -10 dB. The net field strength for comparison to the appropriate emission limit is 32 dBµV/m. This value in dBµV/m was converted to its corresponding level in µV/m. RA = 62.0 dBµV AF = 7.4 dB CF = 1.6 dB AG = 29.0 dB PD = 0 dB AV = -10 dB FS = 62 + 7.4 + 1.6 - 29 + 0 + (-10) = 32 dBµV/m Level in mV/m = Common Antilogarithm [(32 dBµV/m)/20] = 39.8 µV/m FCC ID: NMTTHR128-01 10

INTERTEK TESTING SERVICES 3.2 Radiated Emission Configuration Photograph Worst Case Radiated Emission Front View 433.945 MHz For electronic filing, the front view and back view of test configuration are saved with filename: radiated.jpg. FCC ID: NMTTHR128-01 11

INTERTEK TESTING SERVICES 3.3 Radiated Emission Data The data on the following page lists the significant emission frequencies, the limit and the margin of compliance. Numbers with a minus sign are below the limit. Judgement: Passed by 5.3 dB TEST PERSONNEL: Signature Ken C. C. Lam, Compliance Engineer Typed/Printed Name November 24, 1998 Date FCC ID: NMTTHR128-01 12

INTERTEK TESTING SERVICES Company: IDT Technology Ltd. Date of Test: September 21, 1998 Model: Cable Free Thermo Sensor THR128 Table 1 Radiated Emissions Polarity Frequency Reading Antenna Pre- Average Net Limit Margin (MHz) (dBµV) Factor Amp Factor at 3m at 3m (dB) (dB) Gain (-dB) (dBµV/m) (dBµV/m) (dB) H 433.945 64.4 25.0 16 5.9 67.5 72.8 -5.3 V 867.841 25.1 31.0 16 5.9 34.2 52.8 -18.6 V *1301.838 39.4 25.5 34 5.9 25.0 54.0 -29.0 V 1735.731 39.6 26.5 34 5.9 26.2 52.8 -26.6 V 2169.676 34.6 29.1 34 5.9 23.8 52.8 -29.0 V 2603.621 29.0 34.2 34 5.9 23.3 52.8 -29.5 Notes: 1. Peak Detector Data unless otherwise stated. 2. All measurements were made at 3 meter. Harmonic emissions not detected at the 3-meter distance were measured at 0.3-meter and an inverse proportional extrapolation was performed to compare the signal level to the 3-meter limit. No other harmonic emissions than those reported were detected at a test distance of 0.3-meter. 3. Negative value in the margin column shows emission below limit. 4. Horn antenna and average detector are used for the emission over 1000MHz. *Emission within the restricted band meets the requirement of part 15.205. The corresponding limit as per 15.209 is based on Quasi peak detector data for frequencies below 1000 MHz and average detector data for frequencies over 1000 MHz. Test Engineer: Ken C. C. Lam FCC ID: NMTTHR128-01 13

INTERTEK TESTING SERVICES EXHIBIT 4 EQUIPMENT PHOTOGRAPHS FCC ID: NMTTHR128-01 15

INTERTEK TESTING SERVICES 4.0 Equipment Photographs For electronic filing, photographs of the tested EUT are saved with filename: ophoto1.jpg and ophoto2.jpg for external photo, iphoto1.jpg to iphoto4.jpg for internal photo. FCC ID: NMTTHR128-01 16

INTERTEK TESTING SERVICES EXHIBIT 5 PRODUCT LABELLING FCC ID: NMTTHR128-01 17

INTERTEK TESTING SERVICES 5.0 Product Labelling For electronic filing, the FCC ID label and label location are saved with filename: label.pdf. FCC ID: NMTTHR128-01 18

INTERTEK TESTING SERVICES EXHIBIT 6 TECHNICAL SPECIFICATIONS FCC ID: NMTTHR128-01 19

INTERTEK TESTING SERVICES 6.0 Technical Specifications For electronic filing, the block diagram and schematics of the Low Power Transmitter are saved with filename: block.pdf and circuit.pdf respectively. FCC ID: NMTTHR128-01 20

INTERTEK TESTING SERVICES EXHIBIT 7 INSTRUCTION MANUAL FCC ID: NMTTHR128-01 21

INTERTEK TESTING SERVICES 7.0 Instruction Manual For electronic filing, a preliminary copy of the Instruction Manual is saved with filename: manual.pdf. This manual will be provided to the end-user with each unit sold/leased in the United States. FCC ID: NMTTHR128-01 22

INTERTEK TESTING SERVICES EXHIBIT 8 MISCELLANEOUS INFORMATION FCC ID: NMTTHR128-01 23

INTERTEK TESTING SERVICES 8.0 Miscellaneous Information This miscellaneous information includes details of the measured bandwidth, the test procedure and calculation of factors such as pulse desensitization and averaging factor. FCC ID: NMTTHR128-01 24

INTERTEK TESTING SERVICES 8.1 Measured Bandwidth The plot with filename: bw.pdf shows the fundamental emission when modulated. From the plot, the bandwidth is observed to be 16.5 kHz, at 20 dBc. The bandwidth limit is 1084.8 kHz. Therefore, the unit meets the requirement of Section 15.231(c). FCC ID: NMTTHR128-01 25

INTERTEK TESTING SERVICES 8.2 Discussion of Pulse Desensitization The determination of pulse desensitivity was made in accordance with Hewlett Packard Application Note 150-2, Spectrum Analysis ... Pulsed RF. Pulse desensitivity was not applicable for this device. The effective period (Teff) was approximately 1.5 ms for a digital "1" bit, as shown in the plots of Exhibit 8.3. With a resolution bandwidth (3 dB) of 100 kHz, the pulse desensitivity factor was 0 dB. FCC ID: NMTTHR128-01 26

INTERTEK TESTING SERVICES 8.3 Calculation of Average Factor Averaging factor in dB = 20 log (duty cycle) The specification for output field strengths in accordance with the FCC rules specify measurements with an average detector. During testing, a spectrum analyzer incorporating a peak detector was used. Therefore, a reduction factor can be applied to the resultant peak signal level and compared to the limit for measurement instrumentation incorporating an average detector. The time period over which the duty cycle is measured is 100 milliseconds, or the repetition cycle, whichever is a shorter time frame. The worst case (highest percentage on) duty cycle is used for the calculation. The duty cycle is measured by placing the spectrum analyzer in zero scan (receiver mode) and linear mode at maximum bandwidth (3 MHz at 3 dB down) and viewing the resulting time domain signal output from the analyzer on a Tektronix oscilloscope. The oscilloscope is used because of its superior time base and triggering facilities. A plot of the worst-case duty cycle as detected in this manner is saved with filename: af.pdf for electronic filing. The duty cycle is simply the on-time divided by the period: The duration of one cycle = 100ms Effective period of the cycle = (3 x 5 + 1.5 x 20 + 5.6)ms DC = 50.6ms/100ms= 0.506 or 50.6% Therefore, the averaging factor is found by 20 log10 0.506 = -5.9 dB For electronic filing, the description of transmission data timing and two plots of transmission period and slient period are saved with filename: tx-time.pdf. The slient period is 79 times of the transmission period. Therefore, the EUT meets the automatically limiting operation requirement of section 15.231(e). FCC ID: NMTTHR128-01 27

INTERTEK TESTING SERVICES 8.4 Emissions Test Procedures The following is a description of the test procedure used by Intertek Testing Services in the measurements of transmitters operating under Part 15, Subpart C rules. The test set-up and procedures described below are designed to meet the requirements of ANSI C63.4 - 1992. The transmitting equipment under test (EUT) is attached to a cardboard box and placed on a wooden turntable which is four feet in diameter and approximately one meter in height above the ground plane. During the radiated emissions test, the turntable is rotated and any cables leaving the EUT are manipulated to find the configuration resulting in maximum emissions. The cardboard box is adjusted through all three orthogonal axes to obtain maximum emission levels. The antenna height and polarization are varied during the testing to search for maximum signal levels. Detector function for radiated emissions is in peak mode. Average readings, when required, are taken by measuring the duty cycle of the equipment under test and subtracting the corresponding amount in dB from the measured peak readings. A detailed description for the calculation of the average factor can be found in Exhibit 8.3. The frequency range scanned is from the lowest radio frequency signal generated in the device which is greater than 9 kHz to the tenth harmonic of the highest fundamental frequency or 40 GHz, whichever is lower. For line conducted emissions, the range scanned is 450 kHz to 30 MHz. FCC ID: NMTTHR128-01 28

INTERTEK TESTING SERVICES 8.4 Emissions Test Procedures (cont'd) The EUT is warmed up for 15 minutes prior to the test. AC power to the unit is varied from 85% to 115% nominal and variation in the fundamental emission field strength is recorded. If battery powered, a new, fully charged battery is used. Conducted measurements are made as described in ANSI C63.4 - 1992. The IF bandwidth used for measurement of radiated signal strength was 100 kHz or greater below 1000 MHz. Where pulsed transmissions of short enough pulse duration warrant, a greater bandwidth is selected according to the recommendations of Hewlett Packard Application Note 150-2. A discussion of whether pulse desensitivity is applicable to this unit is included in this report (See Exhibit 8.2). Above 1000 MHz, a resolution bandwidth of 1 MHz is used. Transmitter measurements are normally conducted at a measurement distance of three meters. However, to assure low enough noise floor in the forbidden bands and above 1 GHz, signals are acquired at a distance of one meter or less. All measurements are extrapolated to three meters using inverse scaling, but those measurements taken at a closer distance are so marked. FCC ID: NMTTHR128-01 29


Document Created: 2001-07-10 15:00:06
Document Modified: 2001-07-10 15:00:06
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