A measuring instrument for quantitatively evaluating the cylindricity of a cylinder by measuring the actual contour of the cylinder using the precise rotation centerline as the reference standard and the precise linear motion guide rail as the reference standard. It can be used to measure cylindrical shape errors (roundness, cylindricity, straightness, and flatness), position errors (coaxiality and verticality), etc. The cylindrical Roundness Tester is mainly used to measure the roundness, cylindricity, straightness, concentricity, coaxiality, flatness, parallelism, perpendicularity, surface waviness, discontinuous surface, etc. of various regular and irregular circular workpieces. It can also perform spectrum analysis, wave height analysis, eccentricity, shaft bending analysis, and runout analysis on workpieces. This device has excellent cost-effectiveness, full measurement capability, and is easy to learn and use. Cylindrical Measuring Instrument,Cylindricity Measuring Instrument ,3D Image Measuring Instrument,Roundness Measurement Instrument Zhejiang dexun instrument technology co., ltd , https://www.dexunmeasuring.com
In recent years, improper use of chemical fertilizers by some farmers has led to low efficiency in fertilizer utilization, increased costs, and even crop damage due to overuse or incorrect application. For instance, calcium magnesium phosphate fertilizer, when used as a top dressing, is slower in release compared to other forms, and its limited application window makes it less effective, especially during the later growth stages of crops. This results in poor nutrient absorption and reduced effectiveness. To improve this, calcium magnesium phosphate should be applied as a base fertilizer, mixed with organic materials, or used as a side-dressing. This allows for a slow and steady release of nutrients, supporting long-term crop development without early decline.
Urea and ammonium bicarbonate are often used as surface fertilizers, but despite their high nitrogen content, they must first be converted into ammonium in the soil before being absorbed by plants. During this transformation, urea remains in a molecular form, which can lead to leaching with water, reducing its availability to crops. Ammonium bicarbonate, when applied on the surface, tends to volatilize easily, releasing ammonia that can burn plant leaves and stems, causing damage. When using these nitrogen-based fertilizers as top dressings, it's best to incorporate them into the soil through trenches. Foliar sprays, such as those applied to wheat, rice, cotton, and corn, should be done at concentrations between 0.8% and 1%, while vegetables require lower concentrations, around 0.3% to 0.5%.
Direct application of superphosphate to seeds is not recommended, as it contains 3.5–5% free acid, which can reduce seed germination and emergence rates. Therefore, superphosphate should be applied deeper into the soil as a top dressing. If used as a seed fertilizer, it should be placed 5–6 cm below or beside the seeds, separated by a layer of soil to prevent direct contact.
When applying potassium sulfate or potassium nitrate alone, they tend to be weakly physiologically acidic. Once in the soil, potassium ions are absorbed and replace cations on soil colloids, making it harder for crops to take up the nutrients. To maximize their effectiveness, potash fertilizers should be combined with nitrogenous and phosphate fertilizers. In phosphorus-deficient soils, such as those found in mountainous areas or newly reclaimed land, mixing potash with phosphate fertilizers enhances overall nutrient uptake.
There is also a significant "antagonism" between zinc fertilizer and phosphate fertilizer. When mixed together, the effectiveness of zinc sulfate is reduced. Therefore, it's better to apply phosphate fertilizer as a base fertilizer and zinc as a seedling fertilizer, or vice versa, to avoid this conflict and improve overall efficiency.
Ammonium chloride and potassium chloride contain chloride ions, which can negatively affect certain crops. When applied to sugar cane, watermelon, tobacco, or citrus, chloride can lower sugar content, reduce burning quality in tobacco, and cause chronic toxicity in citrus, leading to dull leaves, stunted growth, and even death in severe cases. Therefore, these fertilizers are more suitable for chloride-tolerant crops like rice, wheat, corn, and cotton, where their benefits can be fully realized without harm.