Laboratory manual for the evaluation of non-automatic weighing devices
LG-3.10 Immunity to radiated electromagnetic field
Table of contents
Section 30 of the Specifications Relating to Non Automatic Weighing Devices (1998)
This test is performed on any complete weighing devices and major elements that incorporate electronic components susceptible to be affected by radiated electromagnetic fields. This test consists of exposing the device to an electromagnetic field emitted by radio transmitters at frequencies of 27 MHz and 460 MHz with an intensity of up to ≈3 V/m.
Note to the attention of device manufacturers
This test method will be used until Measurement Canada acquires the necessary facilities and equipment to perform immunity to radiated electromagnetic field tests over the entire 26 MHz to 1 000 MHz range as recommended by OIML, R76-1).
- The AZT can be in any status.
- Ensure that the radio transceiver batteries have been fully charged.
- Set the IZSM to the maximum of its range.
- The test is performed at ambient temperature only (≈20°C and ≈50% RH).
- The field strength will be measured using an appropriate field strength meter; results of tests while the field intensity exceeding ≈3 V/m will not be considered.
- The determination of error before rounding using the small weights method is not necessary.
- Place, on the platter of the device, a load approximately equal to ½ Max. Record the value displayed.
- Perform a summary test at each radio frequency by bringing the radio antenna close to the DUT at various angles (orientations), above, around and under the device; observe the indication. If the device does not appear to be affected by the RFI, then there is no need to proceed further. If the device is affected, it will be necessary to repeat the test, and this time to measure the field strength at the device.
- Place the field strength meter in close proximity to the device. Using the handheld radio transmitters, expose the DUT to field strength equal to ≈3 V/m. Bring the antenna around, above and under the device, at different angles. Attempt to maintain the field intensity at the device at ≈3 V/m. Observe the indication during the test and attempt to print weight values. Record the results. Do not consider the results obtained while the field strength exceeds ≈3 V/m.
Interpretation of results
The device meets the requirements:
- if the weight indications and registrations with and without disturbance do not exceed the value of e; or
- if the device detects and reacts to a significant fault as follows:
- blanks the indication and prevent the printing of weights; or
- provides an error message and prevent weighing; or
- provides an indication that is completely unstable so that it is not interpreted, or transmitted into memory or to the recording element as a correct measurement value.
- Rev. 1 (March 2010)
- AZSM renamed to AZT
- formatting change
- Date modified: