Data Logger Measurement Know-How

How to Improve the Radio Environment

STEP 1. Review of the attachment method

The signal strength can be improved by adjusting how the measurement units and PC communication unit are attached.

STEP 2. Effective use of a USB extension cable

In cases such as the following, it is recommended to bring the PC communication unit closer to the measurement unit using a USB extension cable.

  • The measurement unit and PC communication unit are too far apart.
  • There is an obstacle between the measurement unit and PC communication unit.

STEP 3. Improvement of the radio environment using a passive antenna

In cases such as the following, it is recommended to use a passive antenna.

  • There is an obstacle made of metal or other material.
  • The PC communication unit cannot be placed because the area is outside the operating temperature range.
  • Radio waves cannot be received without bypassing an obstacle.

STEP 4. Improvement of the radio environment using the passive attachment

In cases such as the following, it is recommended to use the passive attachment.
* The passive attachment can only be used with the WM1000.

  • The radio environment has been improved in STEP 2, but you would like to further improve it.
  • There is an obstacle between measurement units in multi-point measurement and multiple antennas are required.

STEP 1. Review of the attachment method

Wireless Temperature Logger WM1000

  1. When attaching the PC communication unit and measurement units, be sure to attach them in positions where the measurement units are visible from the PC communication unit.
    In addition, if the PC communication unit is placed close to the floor, radio waves coming out of the PC communication unit are absorbed by the floor, so place the PC communication unit at as high a position as possible.
  2. Do not use metal tape such as aluminum tape to attach the temperature measurement unit.
    The metal tape will block radio waves.
    We recommend using resin tape, double-sided tape, or cable ties for attachment under normal conditions, and polyimide tape or silicon tape under high temperatures.

STEP 2. Effective use of a USB extension cable

If there is a metal or concrete wall between the receiver and transmitter, it will obstruct radio waves and hinder communication.
Attach the PC communication unit at a position where it is visible from the measurement units, such as near a window, by using USB extension cable.

STEP 3. Improvement of the radio environment using a passive antenna

What is a Passive Repeater?

A passive repeater is a product in which two 2.4 GHz antenna are connected by a coaxial cable. It does not use an amplifier, so no power supply is required.
When the radio environment deteriorates due to metals or other obstacles, the radio environment may be improved by placing a passive repeater between the temperature measurement unit and PC communication unit.

WM1000 Passive Repeater

Experiment example: Signal strength measurement using a spectrum analyzer

WM1000 Signal strength measurement

STEP 4. Improvement of the radio environment using the passive attachment

What is the passive attachment?

The passive attachment consists of antennas, dividers, and the PC communication fixing package.
By bringing the internal antenna of the PC communication unit and the antenna of the passive attachment closer together, the signal strength improvement effect of the attachment can be maximized.
In addition, signal strength can be improved by attaching a passive relay antenna near the temperature measurement unit experiencing radio wave interference.

WM1000 Passive Attachment

The attachment ports of the dividers are SMA-J connectors; attach the antennas using coaxial cables with SMA-P connectors.

Measurement of Rotating Objects

When the measurement unit is attached on a rotating object, the electrolyte solution of the battery may become lopsided by the centrifugal force and measurement may not be performed.
Place the measurement unit near the center of rotation, where the measurement unit is less likely to be affected by the centrifugal force.

WM1000 Measurement of Rotating Objects