STATUS REPORT OF TIME AND FREQUENCY LAB. (VIETNAM METROLOGY INSTITUTE) Trieu Viet Phuong Head of Time and Frequency Laboratory, VMI Email: phuongtv@vmi.gov.vn DA NANG 11-2016
About TFL Laboratory of time and frequency (TFL) is belonging to VMI. The Lab is a highest laboratory in the fields of Time and frequency in Vietnam testing measurement calibration scheme. There are 7 staffs working at the TFL. The laboratory has been accredited in accordance with ISO/IEC 17025:2005 by Vietnam Laboratory Accreditation Scheme (VILAS). 2
T&F activities Time keeping. Time transfer. Time and frequency disseminations: Calibration and testing services; Internet time service. Researching, designing, manufacturing. Other activities. 3
Time keeping TFL operates three cesium atomic clocks (one of them is high performance cesium beam tube, 5071A with Option 001). UTC(VMI) and VFS are generated from the high performance cesium clock and Auxiliary Output Generator, AOG-110. Three atomic clocks have been compared with one another by the TSC 12030-110. This comparison is performed daily at UTC 0 h (UTC(VMI) + 7 h). The data collected for one month are sent to the BIPM time section. Time and Frequency system at VMI 4
UTC-UTC(VMI) Time keeping 60 40 20 0-20 -40-60 -80 57350 57400 57450 57500 57550 57600 57650 57700-100 UTC(VMI) = UTC + 7 h. UTC - UTC(VMI) < 100 ns, Uncertainty ~ 20.1 ns MJD UTC UTC(VMI) from January to September 2016 5
Time transfer: TAI time link GPS receivers (Javad EU-80 and Septentrio Polarx3e TR) for TAI time comparison network. The GPS observations are measured daily. 6
Time transfer: TAI time link Output files in the format of CGGTTS are sent to BIPM monthly. Output files in the RINEX (from Septentrio PolaR3eTr) is sent to BIPM daily. 7
Internet time service TFL provided NTP service using time server S250i. TFL internet time service uses UTC(VMI) as a reference time. TFL also contributes to standardization of Time Stamping Service (the clock of the time stamping server is calibrated within the prescribed accuracy and traceability to UTC(VMI) for every issued time stamp is assured). Can accept up to 80000 requests per second. 8
Calibration and testing services VMI has been conducting a frequency calibration service referenced to UTC(VMI). The first CMC table was approved and registered in the Key Comparison Database (KCDB). 9
Calibration and testing services Total number: > 300 units/ yearly, included: Universal counters, Signal generators, Local clocks, Quartz oscillators, local frequency standards, Type approval test for taximeters, Automobiles tachograph (GPS tracker, car black box) 10
Researching, designing, manufacturing Researching, designing, manufacturing some equipment such as: power cut/ on warning via SMS system; tachometer; standard for verification of taximeters, and NTP clocks Development of new algorithm and software for steering and keeping of UTC(VMI). 11
Other activities To develop calibration/ verification testing methods. To carry out peer review on the technical aspects of verification bodies, serving the state management on Time and frequency metrology. To develop material for trainings on Time and frequency metrology. To train the technical staffs for the verification, calibration and testing bodies in time and frequency field 12
Future plans To plan for Cesium Beam Tube Replacement (in 2017). To build dual system to generate of UTC(VMI) (after 2017 to 2020). To develop remote calibration services, strengthen international and bilateral comparison with other NMIs. To expand TF s CMC table (after 2017). 13
Thank you for your attention! 14