Overview
According to EN 55015 / 4.4 the magnetic field strength of flourescent lighting luminaires has to be measured, if the operating frequency is above 100 Hz. The measurement is done with a triple loop antenna as shown above. The Unit under Test is positioned under operating conditions in the centre of the triple loop antenna. To measure the magnetic field strength without turning, there are loops in X-,Y- and Zdirection. A current transformer converts the loop current into an appropriate voltage. Ferrite chokes reduce braid current on the coaxial cables which would cause wrong measurement.
The switchbox gives access to one of the three loops via local or remote control. The r. f.-output is connected to the input of an interference measuring receiver. The calibration balun HFCD 9171 substitutes the E.u.T. during calibration. A signal generator may be used as source for the balun. An ideal instrument for measurement and calibration is the Schwarzbeck interference measuring receiver FCKL 1528 with the optional tracking generator, which is also best choice for measuring the insertion loss of luminaires.
| Technical Data | |
| Calibration-Dipole (Balun) HFCD 9171 | |
| Principle | Coaxial constant current loop for calibration of the HXYZ 9170 acc. to EN 55015/B.4. |
| Construction | Coaxial cable fixed to a plastic plate. Metal box with BNC-conn.. |
| Switchbox | |
| Principle | R.f.-switch to select 1 of 3 loops |
| Control | Manually via rotary switch, remote control via a 9-pin sub-d-connector 4 LEDs to monitor the state. |
| Attenuation of selected path | <0,5dB 9k-30MHz Leakage from other paths: >45 dB 9 k-30 MHz |
| Construction | Metal box with 4 BNC-connectors and remote control connector. 4 LEDs. Box can be mounted on the glass fibre tube. |
| Stand | Glass fibre tubes, struts, ground plate. |
| Switchbox | Selector manual and remote control, 3 coaxial cables with ferrite chokes. |
| Calibration dipole (balun) | HFCD 9171 |
Important Note
- The loop antenna consists of 3 loops and 3 current transformers and the mechanic clamps for the fixing of the loops. (Basic components)
- The stand for mounting the loops on the floor (glass fibre tubes, struts, ground plate) are optional.
- The switchbox for both manual and remote control operation is optional.
- The calibration dipole HFCD 9171 is optional.
- The wiring (coaxial r.f.-cables, remote control cable) are optional.
