The TFF sensor should be changed once a year. You can also reorder and install it by yourself. The optics needs to be calibrated once per vehicle. This can be made via the Android/ iOS App in a few simple steps. The application also allows to store different calibration profiles for different vehicles. Therefore you don’t have to calibrate the optics with every vehicle change. However we recommend a calibration interval of every 3 months.

MARWIS is equipped with a combined temperature-humidity-sensor. It is included in the delivery. The sensor should be changed once a year, to provide an exact as possible capture of temperature and humidity. This can be done by the user on site.

The data are not saved, but the configuration will survive.

When the Bluetooth connection between MARWIS and mobile output device is interrupted, no data will be saved. If the connection between the output device and the server is interrupted, the app saves the data and transfers them with the next connection to the server. The duration of the saving depends on the storage capacity of the main storage. Normally the main storage is about 2 GB, which is enough for several hours.

The GPS position will be determined by the smartphone or tablet.

MARWIS measures the following data:Dew point temperature, road surface temperature, relative humidity over the road surface, water film height and road condition (dry, wet, moist, frozen, snow/ice, critical wetness)

The relative humidity close to the street behaves differently from the one in the ambient air and represents a more exact picture of the actual road weather conditions (micro climate). For instance the question when white frost arises can be answered better with this value. With MARIW 2.0 the relative humidity in the ambient air can be determined as well.

The dew point temperature is the temperature, at which water steam in form of dew or fog separates from wet air. At the dew point the relative humidity counts 100 percent respectively it means that the air is (just) saturated. The dew point temperature for MARWIS is independent from the relative humidity directly above the road surface. This is why it delivers more important data for the road safety than the air temperature.

The cigarette lighter of a normal passenger car has a voltage of 12 Voltage. But in order to reach the maximum heating requirement of the MARWIS 24 Volts are required. If your MARWIS often runs with a yellow status LED continuously, we recommend a DC / DC converter such as the Samlex Step Up Converter Step 7 (price about 100 $ on Amazon).

The pyrometer measurement is never adjusted automatically, only manually. Therefore an offset for the pyrometer can be configured in the sensor settings. Precondition is an installed sensor firmware version from 1.8 on and an iOS app version from 1.5 on. Please measure the road temperature with a reliable reference instrument at the same spot, after MARWIS has been running for at least 10 minutes and the LED have switched to green already. Then, adjust the temperature measurement in the setting menu. For this, the –/-/+/++ buttons must be pushed until the wished temperature is reached (after pushing the buttons wait until the pyrometer is updated with the new emission level). Sensor configuration description on iOS app help as well as on the Android App help website.

Since firmware version 23 MARWIS can be used with CAN-BUS on default.

In principle, you have the free choice of the Android tablet. However, it is recommended that it has a 8-inch display size maximally in order to avoid an interference with the street view, such as the Samsung Galaxy Tab 4 (7.0, LTE). Also, it only works with the Android version 4.1 or newer. For the use with ViewMondo, MARWIS requires an UMTS/ LTE (international 3G / 4G) sim card.

Generally the display must never be switched off for the guaranteed data transfer and the app must be running in the foreground. In case the vehicle is at a standstill for a while, the data acquisition is turned off by default after 10 minutes. In the device settings, this time can be extended to 2 hours for stationary operation. In display mode, the standard charger is not sufficient for charging. We recommend to e.g. use the Belkin car charger (2.4 Amp/ 12 Watt). Then the battery of the iPad is also loaded when the display is always switched on.

The new MARWIS version is equipped with an additional temperature humidity sensor, which is visible in the sensor component’s description at “specifications”. This new element measures the ambient temperature and detects the ambient relative humidity.