Is it normal for the laser level to have heavy lines? How to solve it?

  The construction plan of the laser leveling machine is as follows Requirements for the base surface: The base surface must be firm, compacted, without settlement, cracking, no oil stains, no plastic film, no other paint, latex paint, bubble gum and other residues on the ground, and the base surface must be flat without large ups and downs, no bumps, honeycombs, or cement lumps. 1. Rolling of the bare soil, requiring compaction and flatness error of 2~3cm∕2m. 2. Pad construction: Use C15 fine stone concrete to cast a 6 cm thick pad layer, vibrate with a vibration pump, and the surface does not need to be smoothed. The flatness is maintained at 2cm∕2m. (This item is optional) 1. Ground treatment After the general contractor and the relevant construction parties have cleared away the large building materials and garbage in the construction area where the 6 cm cushion layer has been laid and handed it over to us, we will first clean up the dust in this area. If there is paint or other foreign matter that is not easy to combine with concrete on the ground, we must do everything we can to remove it. Then rinse the ground with water, and there must be no floating dust. If the base layer is higher in special places, it should be chiseled off with an electric pick or air compressor. 2. Preliminary measurement of elevation According to the basic elevation points given by the general contractor or Party A, the elevation of representative locations in the entire area is initially measured with a level to see how much the thickness of the concrete differs from the thickness required by the owner. (This measurement should be as many points as possible, otherwise it is not representative). In most cases, since the flatness of the base layer is not well controlled, once the elevation is measured, it can be seen how thick and thin the thick and thin parts and the thickness of most concrete are. If the thickness of most concrete exceeds the contract thickness, or is much lower than the contract thickness, the situation should be reported to the superior truthfully and a solution should be requested before the next step of construction can be carried out. 3. Rebar binding For the thicker 20cm thick floor poured in this project, according to the design requirements, double-layer bidirectional reinforcement is generally required. The reinforcement arrangement requires Φ12@150*150, and the upper and lower layers are connected by horse stools. The distance between horse stools is 1 meter. The surface layer reinforcement is 3~4 cm away from the floor elevation. In order to prevent the floor from settling, it is recommended to set up an integral continuous steel mesh. Or pour in separate compartments, but use force transfer rods to connect the plates. The force transfer rods can be Φ20@1000 round steel bars, with a spacing of 400. 4. Formwork 1.) According to the elevation confirmed by Party A, the template position is determined according to the floor drain position and water collection well position listed in the drawings and the slope requirements. This project is in an underground garage, and there may be a slope requirement, so the template can use angle irons of different specifications from Ф6.5*6.5*5 to Ф3*3*2 as the template. Use large specifications for thick concrete and small specifications for thin concrete. According to the designed slope, the compartment casting method is adopted. 2.) The leveling of this project needs to be leveled by a laser leveler. The uniform high-frequency vibration of the laser leveler makes the concrete floor dense and avoids the stress concentration caused by deformation and cracking of the floor. When using a laser leveler for leveling, you only need to make the frame template of each piece. When supporting the formwork, first use an ink fountain to pop up the template control line on the base ground. The line is appropriately wider than the edge of the future compartment seam by 1~2 cm, so that after the formwork is removed, the side seam is not straight due to local damage, and it can also be trimmed. If it can be guaranteed that the side seam after each demolding is a straight line, the template can also be directly supported on the natural seam of the future axis. 3.) On the control line, drill holes on the ground with an electric hammer every one meter or so. Generally, a 12×200 drill bit is used, and the penetration depth is about 14 cm. 4.) Nail the steel bars with a diameter of 12 mm cut into 14 cm each section into the drilled holes. It is required to be firmly driven until it can hardly be driven down. 5.) Place the angle iron near the firmly driven steel bars along the line direction. First, use wood or bricks to pad the two ends of the angle iron. The approximate height is about the same as the elevation. Then one person looks at the level, one person holds the tower ruler, and another person uses a wooden wedge to fine-tune the height of the angle iron at any time according to the elevation. After reaching the same elevation, the electric welder spot welds the angle iron to the top of the steel bar. Then weld the other end of the angle iron in the same way. After both ends are welded, weld the middle part of the angle iron. After welding, check the elevation of one side again. 6) Brush the template oil (waste engine oil) on the supported template to facilitate demoulding. 7) After the compartment formwork is supported, the angle irons are welded around the water collection well. The upper end of the angle iron should be consistent with the floor slope of the compartment, and ensure that water is concentrated to the water collection well from multiple directions. 8) The construction method of the angle irons at the edge of the water collection well for the first floor with only floor drains but no water collection well and car ramp is the same as in Article 7.

The laser receiver is one of the core equipment in laser leveling construction, and the evaluation of its sensitivity and dynamic range is crucial to ensure construction quality. Sensitivity determines the minimum signal strength that a laser receiver can detect, while dynamic range reflects the laser receiver's ability to work under different signal strengths. This article will elaborate on how to evaluate the sensitivity and dynamic range of the laser receiver, in order to provide a useful reference for improving the quality of laser leveling construction in floor projects. 1. Evaluation of sensitivity The sensitivity of a laser receiver is usually expressed in terms of the minimum optical power or minimum light intensity that can be detected. Assessing the sensitivity of a laser receiver requires the following steps: •♦•Choose an appropriate test light source: In order to ensure the accuracy and reliability of the evaluation results, it is necessary to select a stable and adjustable test light source. The wavelength of the test light source should match the design wavelength of the laser receiver. To ensure the validity of the test, •♦•Set test conditions: During the test process, environmental variables such as temperature, humidity and vibration need to be controlled to reduce test errors. At the same time, the test distance and angle should also be set according to the actual usage of the laser receiver. •♦•Measurement of optical power or intensity: Use measuring equipment such as an optical power meter or intensity meter to measure the response of the laser receiver under different optical powers or intensity. Recording the minimum optical power or light intensity value that can trigger the response of the laser receiver is the sensitivity of the laser receiver. It should be noted that when evaluating the sensitivity of the laser receiver, it is also necessary to consider the impact of parameters such as spot diameter and divergence angle on the test results. In addition, since the laser receiver may be interfered by background light, noise and other factors, corresponding measures should be taken during the evaluation process to reduce the impact of interference on the test results. 2. Assessment of dynamic range The dynamic range of a laser receiver refers to the range between the maximum optical power and the minimum optical power that the base can handle. To evaluate the dynamic range of a laser receiver, you need to take the following steps: •♦•Determine the maximum optical power threshold:  First, you need to determine the maximum optical power that the laser receiver can withstand, which can usually be obtained by consulting the technical specifications of the laser receiver or conducting actual tests. During the actual test process, you can gradually increase the optical power and observe the response of the laser receiver until saturation or damage occurs. Record the optical power value at this time, which is the maximum optical power threshold of the laser receiver. •♦•Determine the minimum optical power threshold: As mentioned above, the minimum optical power threshold of the laser receiver can be obtained through sensitivity evaluation. That is, the minimum optical power value that can trigger the response of the laser receiver. •♦•Calculate dynamic range: Calculate the dynamic range of the laser receiver based on the maximum optical power threshold and the minimum optical power threshold. Dynamic range is usually expressed in decibels (dB), and the calculation formula is: dynamic range (dB) = 10*log10 (maximum optical power/minimum optical power). It should be noted that when evaluating the dynamic range of a laser receiver, other factors such as linearity, noise, etc. should also be considered. Linearity reflects whether the response of the laser receiver under different optical powers is linear and is crucial to ensuring measurement accuracy. Noise may have a negative impact on the performance of the laser receiver and needs to be paid attention to in practical evaluations. In addition, in order to improve the accuracy and reliability of the evaluation results, it is recommended to use a variety of different testing methods and equipment for evaluation. For example, you can use test light sources of different wavelengths, change the test distance and angle, and other conditions to observe the response of the laser receiver. At the same time, you can also conduct comparative tests with other laser receivers of the same type to better understand the performance characteristics of the laser receiver. Summarize The evaluation of the sensitivity and dynamic range of the laser receiver is an important part of ensuring the quality of laser leveling construction for floor projects. The performance characteristics of a laser receiver can be fully evaluated by selecting the appropriate test light source and test conditions, making optical power or intensity measurements, and calculating dynamic range. In the actual evaluation process, attention should also be paid to the impact of other factors such as linearity, noise, etc. on the evaluation results. Through scientific and reasonable evaluation methods and technical means, useful reference and support can be provided to improve the quality of laser leveling construction of floor projects.

    The performance of a concrete laser leveling machine is highly dependent on the slump of the concrete. Slump not only reflects the flowability of the concrete but also directly affects the resistance of the leveling head and the density of the finished product. For concrete with different slumps, operators need to adjust the vibration frequency, paving height, machine travel speed, and the downward pressure of the auger to ensure the quality of the flooring. This mix is ​​typically used for heavy-duty industrial floors or areas requiring high strength. The concrete is relatively "dry" and has poor flowability. Vibration frequency: Requires adjustment to a higher frequency (usually increasing by 10%–20%). Dry, stiff concrete requires stronger vibration to remove air bubbles and allow the slurry to float. Travel speed: Slow. A slow travel speed allows sufficient compaction time for the leveling head, preventing surface "tearing" or honeycomb pitting caused by excessively rapid movement. Auger adjustment: Increase downforce to allow the auger to cut deeper into the concrete, ensuring large aggregate particles are effectively leveled. Plow height: Slightly lower the slow height. Because dry concrete has less rebound after leveling, the initial leveling needs to be closer to the design elevation. This is the ideal working range for laser leveling, balancing pumpability and structural stability. Vibration Frequency: Maintain a medium standard frequency. Travel Speed: Medium speed. Observe the slurry thickness behind the leveling head to ensure a uniform "skin" (slurry layer) on the surface. Overlap: Maintain a standard 200mm–300mm overlap to eliminate seam marks between adjacent passes. Common in projects using high-efficiency water-reducing agents or with high pumping heights. The concrete is extremely fluid and may even exhibit segregation. Vibration Frequency: Adjust to a low frequency or reduce it appropriately. Excessive vibration can cause mortar and aggregate separation (segregation), resulting in a large amount of laitance and potential sandiness on the surface. Travel Speed: Can be appropriately increased. Prevent the machine from remaining stationary in one spot for extended periods, which could lead to excessive subsidence in that area. Auger Adjustment: Reduce the auger pressure or raise its position. High slump concrete is very mobile; the auger only needs to guide the flow slightly. Excessive agitation will disrupt the levelness. Scraper Height: Set the scraper height slightly above the design elevation (approximately 3mm–5mm) to compensate for the slight settling of the high-flowability concrete after compaction. Adjustment items Low slump (dry) High slump (thin) Vibration frequency ↑ High frequency (strong vibration compaction) ↓ Low frequency (prevents segregation) Travel speed ↓ Slow speed (fine grinding) ↑ Relatively fast speed (uniform spreading) Auger depth Deeper (forced material discharge) Relatively shallow (slight guidance) Elevation allowance Less (low rebound) More (significant settlement) Risk points Surface cracking, poor flatness Excessive slurry thickness, later peeling, slope loss   On construction sites, the slump of concrete often fluctuates as the mixer trucks arrive. A skilled observer will closely follow the machine, monitoring the cream thickness behind the leveling head. If the cream thickness exceeds 5mm, the concrete is too thin; the speed should be increased or the vibration reduced. If the surface is dry and the aggregate is exposed, it is too dry; the walking speed should be immediately reduced and the vibration increased.   Note: The parameters provided in this document are for reference only and are not mandatory. Due to differences in technical characteristics between different brands and models of laser levelers, please consult the manufacturer for a suitable solution before actual operation. This reference document assumes no responsibility for any issues arising from failure to follow the manufacturer's instructions.