A transit is used in the landscape industry to measure vertical and horizontal angles to determine the difference in elevation on a straight line. It is a telescope that telescope that revolves around a horizontal and vertical axes, with mechanisms to measure angles. It reads the measurements so you can use them to map a sit and find the position to find the boundaries of the land area.
Things you will need
- A transit
- A Tripod
- Level screws
- Plumb bob
- Place the tripod on the ground so that it is close to one of the marked points and spread its legs about three (3) feet apart to stabilize the tripod. This location will be called your instrument point. Adjust the tripod so that the upper plate is horizontal and near to your chin.
- Take out the transit and use your hand to hold it in until it is completely connected to the tripod. Use a plumb bob or an optical plummet to place the tripod and transit over the Instrument Point (IP). Adjust the tripod legs and place the legs of the tripod into the ground so it becomes leveled and the center of the instrument goes directly over the Instrument Point (IP).
- Use level screws and level the transit by checking through 360 degrees of rotation. Start with the plate bubble parallel to the two leveling screws. If you want to adjust it, turn one screw clockwise and the other counter-clockwise at the same time and then rotate the telescope 90 degrees and re-level the instrument.
- Repeat this process in 90 degree increments until the plate bubble remains in the same position throughout the entire circle. Before each reading, check the level bubble. The transit will begin to heat up and expand when the sun starts shining on it by then you will have to re-level the instrument.
- Set the horizontal angle to 0 and sight the other known point called the Backsight Point (BS). Look where the electronic transits are to find a button named ‘0SET’, when you have found the other point on the Backsight Point then push this button. Use the upper motion to set the horizontal reading to 0 and then set the lower motion to sight on the Backsight Point (BS).
- Then measure the distance between the two points and use the transit. Use the Backsight Point and the Instrument Point to establish a distance known as the baseline. Then map the features by reading the horizontal angles to each feature from both points.
- This measurement can also be used to find out the elevation by reading the horizontal and vertical angles from both points.
Do’s and Don’ts
- Do not allow the transit to fall. It is fragile and a fall may damage it, costing you hundreds of dollars to repair or replace.