How to measure. Telemeter Guide.

Measurement basics

 To start measurements go to the "Preferences" first. Choose a measurement mode: Hand-Mode or Stand-Mode (see picture on the right). Then enter the Height according to the selected mode.

Choose "Hand-Mode" when the exact height of the device is unknown and you are on the ground holding the device in you hands (picture below). Then enter your current height into Your Height line in Preferences.

 Your Height is a user height (second picture on the right). This value is used to estimate the actual height of the device.
Picture shows how Telemeter is used in Hand-Mode and Stand-Mode and what Height (H) means in each case.


If the exact height of the device is known, "Stand-Mode" is to be chosen as a measurement mode in Preferences. Stand Height here is the exact distance from the ground to the phone.



In order to make correct measurements of depth/length, width, height or distance to object, follow simple measurement rules, depending on the selected mode.

1. In "Hand-Mode" hold the device in proper position and move it properly to achieve more accurate results. Pictures below shows the right way to hold the device in Hand-Mode.



You phone must be positioned on the same horizontal line with your mouth. The proper position can be verified in the following way: if you hold the device in the right position and the screen of the device is turned off (used as a mirror), you will see the reflection of your mouth on the screen. This position corresponds to "natural" device position, when you try to take a picture with your camera. The proper phone position in Hand-Mode is crucial to achieving correct results!

2. In all point-to-point measurements like depth/length, width and height the proper device position and motion from a source point to a destination point are crucial. Pictures below shows the incorrect(left) and correct(right) way to move the device.

Rotate your phone around the original position, but do not move or translate it. This is very important for right measurement results. The same movement rule is applied in Stand-Mode.


3. Bubble Line (Spirit Level) appears in different measurement modes and is shown on the picture. 


It is used as an auxiliary tool to keep the phone in proper orientation, acceptable to perform measurements. During measurements make sure that the bubble is always in the center of the line. In this case the bubble line appears green.  Green color indicates that the phone orientation is correct and you can execute measurements properly.
 
4. Before taking any  measurements make sure that the phone is calibrated. It is very important for  acceptable and repeatable results! Please, check the "Calibration"  section of this manual for details.

5. If you have started a measurement, keep your location and camera position at the same spot and level till the end of the measurement.

For example, if you have measured the distance D to a wall and then you want to measure height of the object on this wall, keep the initial position. Do not walk between these measurements  and do not change the phone height! Otherwise start this procedure from the very beginning  by taking the distance to the wall  from your new location.



Calibration

For the best measurement results it is required to calibrated your device at first. Please press "Calibration" button
from the Intro screen or select [Menu > Preferences > Calibration] from any tool. Place the phone on an ideally horizontal surface like desk, floor, etc. and press the button "Press to calibrate".



Compass Calibration:

hold your phone and rotate your wrist in figure eight(8) to recalibrate it. You may need to repeat this procedure at intervals - this is a feature of the compass sensor, that requires recalibration after magnetic field interference, rather than Telemeter App.

Three-State Measurement Principle



In the point-to-point measurements like depth/length, width, height  or angles, where the cross-hair moves from a source to a destination point,  three-state principle is used. These three states are shown i the picture below:
  • "released"-state
  • "focusing"-state
  • "snapshot"-state



After pointing the device at the source point, press the camera button half-way down ("focusing"- state) to start measurements and release the button ("released"-state) at the destination point to complete the measurement.

For distance measurements from you to an object or to a specific point on the ground-level "snapshot"-state is used.
In other words, the "focusing"-state and the "released"-state are used to start and to end the point-to-point measurement respectively. In one-point measurements like distance to an object the "snapshot"-state is used.


Attention: If your phone does not have a camera button, touch screen is used to perform measurements. In this case the first tap and the second tap are used to start and to end the point-to-point measurement respectively. In the one-point measurement (like distance to an object) the long tap is employed.

Distance measurement to an object (distance from an observer)


For example, an observer wants to measure the distance to a wall. The picture  (on the right) shows the real scene where measurements were taken. The observer position and the scene are illustrated schematically on the left bottom picture. The bottom right picture is the device screenshot during the measurement.



In order to measure the distance from the user to the wall,  the cross-hair in the center of the screen has to be pointed to the intersection of the wall baseline and the perpendicular line from the user to the wall, see the schematic picture and screenshot below. To complete the measurement make a long tap (or press the camera button all the way down (snapshot-state) as you would usually take a picture). More about the measurement principle in the section Three-State Measurement Principle.


How to measure object depth (distance between two points in the direction "from observer")


Here "depth" means the size of an object or simple distance between two points in the direction "from observer". In order to measure it, aim the cross-hair at "start point"  (be sure that the bubble level underneath  the cross-hair is centered), tap the screen once (or click and hold(!) the "camera"-button in focusing state) and then move the cross-hair to the "end point" (the bubble level must be centered at this point too), tap the screen again (or release the "camera"-button) to complete measurement. (Read Three-State Measurement Principle about the specific use  of the "camera"-button" during measurements.) 



How to measure object height 

   

The height of the object from the ground level (a) or vertical distance between two points (b) on a wall (see pictures on the right) can be measured in "HEIGHT"-mode.

The figures and screenshots below show this two scenarios, but the measurement principle is the same. It is important to mention, that distance to the object/wall (D) should be measured first(!) by pointing the cross-hair at the ground point of the object or plane. 

Be sure that the bubble level underneath  is centered, green color of the cross-hair indicates the proper camera orientation to start the measurement.

     

Measurement steps are:
  1. Point the cross-hair at the ground point of the wall, where object is placed. Make a long tap (or press the "camera"-button all the way down to the snapshot-state) to complete the measurement of the distance to the object/wall.
  2. After the distance to the object/wall is known, the height can be measured. Aim the cross-hair at "start point" and tap the screen once (or press "camera"-button half way down to the "focusing-state"). Then move the cross-hair to the "end point" and tap the screen once again (or release the "camera"-button).
Note: The touch screen or "camera"-button are used the same way as in the "DEPTH"-mode, check Three-State Principle for details.

The pictures below explain the measurement steps. The screenshots show the measurement process and the results: D - distance to the wall, H - height between two points. Read more about the measurement screen and symbols on it in this section.
 measure the distance to the wall first (!)


a)
 measure the distance (height) from the ground  ...


... to the bottom line of the picture



b)

 measure the height of the picture from the bottom point ...
... to the point on the top





How to measure object width


    The "WIDTH"-mode is used to measure horizontal(!)  distance between two points in a plane (on a wall). Steps are similar as in "HEIGHT" mode.

  1. Point the cross-hair at the ground point of the wall, where object is placed. Make a long tap (or press the "camera"-button all the way down to the snapshot-state) to take the distance to the object/wall first.
  2. After the distance to the object/wall is measured, the width can be measured. Aim the cross-hair at "start point" and tap the screen once (or press "camera"-button to "focusing-state").  Then move the cross-hair to the "end point" and tap the screen again (or release the "camera"-button).
Attention: Since the  compass sensor is used for measurement in this mode and it has relatively slow response, wait 5-7 seconds at start and end points until measured value is settled.
Due to height sensitivity to the electromagnetic interference, magnets and metallic objects, accuracy of all measurements, based on the compass sensor, varies significantly depending on surroundings. Calibrating the compass may improve the result of measurement.






How to align a horizontal plane (like table, panel, wall, etc.)

"Spirit Level" Tool is used to indicate whether a surface is sufficiently horizontal or vertical.
It works like a simple spirit level but in 2 dimensions and can be used either as a "contact" (in touch with objects as on the pictures below) or as a "non-contact" (visually, using camera) tool to align distant objects.

If the respective bubble is centered and the axis is green colored, a surface is sufficiently horizontal or vertical in direction of this axis.


How to determine the orientation


Sometimes it is necessary to determine the orientation in the room. The "Compass" Tool uses the compass sensor to do it. Aim the cross-hair towards an object or any direction around and you will see on the screen exact orientation and angle value relative to the North augmented with the scene on the screen.

The pictures and screenshot show the wall orientation:
line with the "bubble"-end indicates orientation of the cross-hair/wall with respect to the North.  Blue sector represents the deflection angle, which is stated as "Orientation to North" in the left corner of the screen.

Attention: Use spirit level at the bottom to keep the device aligned correctly.
If the device is not aligned properly, the compass doesn't show the wrong orientation values.  It is made to ensure valid and accurate result.

Since the  compass sensor is used for measurement in this mode and it has relatively slow response, wait 2-3 seconds until measured value is settled.
Due to high sensitivity to the electromagnetic interference and metallic objects, accuracy of all measurements, based on the compass sensor, varies significantly depending on surroundings. Calibrating the compass may improve the result of measurement.





How to determine angle between two vertical planes/walls or two directions in a room


"Compass" Tool is used for this purpose.
To measure the angle between planes or walls:
  • hold the device against a vertical wall (or plane) so the cross-hair pointed into the wall.
  • tap the screen once (or press the "camera"-button half way down to "focusing"-state  and hold it). It fixes the first angle α1 (check screenshots beneath)
  • hold the device against another wall or plane and tap the screen (release the "camera"-button). It fixes the second angle α2 and calculate the difference between the angles in both (cw/ccw) directions. Green sector represents the angle between walls/planes.
  • tap the screen again or press the "camera"-button to reset the measurement.
The same measurement algorithm can be used to measure the angle between two directions in the space/room. In this case aim the cross-hair towards the desired directions. 
Attention: Use spirit level at the bottom to keep the device aligned correctly(!). Since the compass sensor is used for measurement in this mode and it has relatively slow response, wait 5-7 seconds until measured value is settled.
Due to hight sensitivity to the electromagnetic interference and metallic objects, accuracy of all measurements, based on the compass sensor, varies significantly depending on surroundings. Calibrating the compass may improve the result of measurement.




How to detect metallic objects or electric wiring in a wall


"Compass" Tool can be used also in this case.   
This is very useful feature if you need to do a quick check but don't have special tools. It uses high sensitivity of the compass sensor to the electromagnetic interference and metallic objects. Check video below.
 

How to align an object horizontally (picture, shelf, etc)

   



        Make sure your phone is calibrated before using this mode!


    This mode is called "Lines"-mode and is used when vertical or horizontal reference line is needed for alignment (picture on the right). This is very practical tool  and very simple to use,  because it doesn't depend on the device rotation. The only restriction is to keep your phone parallel to the wall/plane. Spirit-level (bubble on the vertical line) helps you to keep right alignment. 

An example of this mode application is shown on the picture and screenshot below.



How to measure  or lay off angles


One more  very interesting feature allows to measure or lay off angles in vertical or horizontal planes. The "Angles"-mode is used for this purpose. Device has to be parallel to the plane of interest. Check spirit levels in the corner to keep correct alignment. The sensor switches  automatically for horizontal or vertical plane measurements.
To measure or lay off the angle :
  • tap the screen once (or press the "camera"-button half way down ("focusing"-state)  and hold it. It starts the measurement.
  • rotate the device about the screen axis (cw/ccw). The gray sector represents current angle value (check the screenshot below).
  • tap the screen (release the "camera"-button) to fix the current angle.
  • tap the screen again or press the "camera"-button to reset the measurement.