Thursday, March 15, 2018

How to determine a good car window tint film from TSER, UVR and VLT values?

The performance of car window tint film is generally determined by these 3 values:

  • TSER - Total Solar Energy Rejected. This is the overall solar energy filtered by the film. The higher the TSER, the more heat from sun is blocked from entering into your car through its windscreens and windows.
  • UVR - Ultraviolet Rejection. Ultraviolet rays can cause colour fading in upholstery and furnishings. It can also cause skin damage and skin cancer.
  • VLT - Visible Light Transmission. This is determined by the darkness of the film. The darker the film, the lower its VLT will be. Note that JPJ has regulation for the minimum amount of VLT allowed for the tint film, so the VLT need to be equal or above the permitted value to abide to the regulation imposed. As VLT contributes quite a large portion of TSER, it will affect the TSER value pretty significantly.

Traditionally, many tint shops tend to use IRR (infra-red rejection) as an indicator, but the infra-red wavelength spectrum is very long and there is no standard of how much of the spectrum to be used to measure IRR, some products claim to have high IRR by measuring only a short portion of it right after the visible light spectrum, which does not have much meaning for the real heat rejection performance measurement. Therefore, unless the wavelength spectrum of IRR is clearly specified and the measurement is until 2,500 nm or more, otherwise this value can be neglected as TSER can provide a more meaningful value for consideration.

So, how to determine a tint film is good, moderate or poor, based on its TSER, UVR and VLT values?

First we look at VLT value, as it's minimum requirement is regulated in Malaysia. A good VLT value should be as low as possible (so that the TSER value will also be lower) but should not gone below the JPJ standard. Otherwise, the enforcement officer may ask you to remove your tints from your windows due to violation of this regulation.

The minimum allowed VLT currently imposed by JPJ is as follow:
  • Front windscreen: 70%
  • Front side windows: 50%
  • Rear side windows: 30%
  • Rear windscreen: 30%

The MS2669:2017 standard has set the requirements for tint film for the following 3 tests:
  • Solar test: VLT, UVT (opposite of UVR) and TSET (opposite of TSER).
  • Weathering test: TSET/TSER value should be stable for a period of 5 years with less than 4% degradation. This is simulated with 1,000 hours shining from solar mercury lamp.
  • Boil test: the tint film should not form bubbles under high temperature.

With reference to this MS2669:2017 standard, we can then determine the range of TSER and UVR which is considered to be good, moderate or marginal only.

  • Good: > 50%
  • Moderate: 39% - 49.99%
  • Marginal: 25% - 38.99%
  • Failed: below 25%

  • Good: > 99.5%
  • Moderate: 98.5% - 99.49%
  • Marginal: 98% - 98.49%
  • Failed: below 98%

Monday, March 5, 2018

My Remax CR-3XP Alien series 1-to-5 smart car charger

With more and more electronic gadgets such as air sterilizer, dashcam, GPS, etc. in the car, couple with the occasional need to recharge my phone and/or tablet while driving, the available charging sockets in my car is not sufficient to provide power to so much devices at the same time.

My solution is to have the Remax CR-3XP Alien series 1-to-5 smart car charger that can extend one car charging socket into 2 charging sockets with independent switch and 3 USB charging ports with combined power output of up to 3.4A.

This Remax CR-3XP smart car charger is designed to sit nicely in the car cup holder. It has 2 colour options: black+gold and white. The black+gold one looks nicer and is pretty hot selling, easily got sold out in the online shops.

This Remax CR-3XP smart car charger has an LED display, which will show the car battery voltage when its 3 USB charging ports are not in used. When either one or more of its USB ports is charging some gadget, the LED display will show the charging amperage.

The photo below shows my Remax CR-3XP smart car charger in action, sitting nicely in one of the car cup holders, with one of its charging sockets connected to my MedKlinn Autoplus air sterilizer.

You can notice that there are 2 buttons beside the LED display, one on its right and another on its left, which can be used to switch on/off the power supply to its 2 charging sockets respectively.

Saturday, February 17, 2018

Converting video files to be playable from USB drive in Honda 39102-T9A-T8XX-M1 display audio head unit

The Honda 39102-T9A-T8XX-M1 display audio is the stock head unit of Honda City 2017 Facelift 1.5L E/V variants.

It is able to play 4 types of multimedia files in a USB thumb drive: MP3 music, WMA music, JPEG photo, and MP4 video.

When the car parking handbrake is engaged, the video will display on the screen, otherwise, the video will become a blue screen while the music in the MP4 continue playing. This is a safety feature so that the driver will focus on driving instead of watching video on the screen. If you want to bypass this safety feature, you can search for a compatible "bypass cable" for this head unit and install it.

In order for any video to be playable in this Honda 39102-T9A-T8XX-M1 head unit, you need to convert it into MP4 format with the following custom settings:

  • Frame size: 640 x 480
  • Adjustment: Original
  • Video codec: MPEG4
  • Frame rate: 15 fps
  • Bitrate type: Auto
  • Audio codec: MP3
  • Channels: Stereo
  • Sample rate: 48000 Hz
  • Audio Bitrate: 320 Kbps

Conversion can be done using a free software called Freemake Video Converter.

Although the car audio manual claimed that it is able to play video in H.264 Base Line Profile format, I have not succeed to make it work with any H.264 video.

The car audio manual also claimed that it is able to support video frame rate up to 30 fps, but if you set the fps higher than 15, the video might not be playing smoothly on the screen.

As the car audio manual has stated that it supports VGA size video only, the frame size is best to be 640x480. If you set it higher than that, the video will be totally unplayable with the "not supported resolution type" error.

Luckily, this head unit is capable to play MP3 in pretty high sample rate and bitrate. Its music playing capability is quite OK, particularly with the 8 speakers in the V variant, despite its video playing capability is really primitive.

Hint: Click on the "Older Posts" link to continue reading, or click here for a listing of all my past 3 months articles.