When you are researching压力计sfor your pressure measurement needs, consider these factors: What is the application? How much pressure is involved? What size dial should you buy? What is the gauge accuracy requirement?
These are just some of the questions to ask that can help you find the proper range for your pressure gauge. It’s easy to be overwhelmed by choices, so this article will offer some tips for selecting the right pressure gauge range for your application.
拨号尺寸和功能
根据您需要的范围，购买量规时有许多拨号选项需要考虑。拨号尺寸的范围从1¼英寸到16英寸。
Why is that?Scales include numerals, major graduations and minor graduations(see Figure 1).
图1：
Those minor graduations can be difficult to read if they’re too close together, so consider readability when selecting a dial size. How far away would it be from sight? It should be large enough to be easily read from distances and angles.
Note that the pointer width cannot be greater than the width of the dial graduations. Pointer width may be a limiting factor when determining how many graduations are available with corresponding dial sizes.
一种space restriction where the gauge will be installed is another consideration when selecting dial size.
是否需要在弱光条件下读取规格？如果是这样，一个很好的选择是使用逆转录拨号材料（如Ashcroft Duravis™仪表表盘。逆转录材料与停车标志上使用的材料相同。
与将光线分散在不同方向的反射材料不同，Duravis™材料将光反射回光源，从而使可读性更容易（见图2）。
图2：
Gauge dial printing is offered to accommodate and personalize the gauge for the application.
产品可以包括彩色拨号，带有彩色区域的表盘，特殊的拨号标记，拨号上的客户名称和虚假读取表盘，仅命名一些选项。
彩色区域表盘的一个示例可能是颜色绿色（安全到操作区域），黄色（警告操作区域）和红色（对操作区域的危险）。表盘上的个性化名称可以包括客户的名称，URL，电话号码和客户徽标（请参见图3）。
Figure 3:
通常，仪表的表盘弧计为270度一种SMEB40.100 guidelines. There are, however, some dial arcs that are less than 270 degrees.
比例选项
需要哪个测量单位？美国的约定通常是pound of force per square inch orpsi。一些最受欢迎的度量单位包括KPA，KG和Bar。
您的申请是否需要两个措施单位的拨号？如果是这样，通常将大多数读取的主要尺度是内部尺度，其中数字和毕业大于外部尺度。
实际上，有各种规模的选择consider选择仪表范围时。一种side from single scale and dual scale, your gauge can measure triple or even quadruple scale depending on how many measurements you need.
There are also refrigerant scales like ammonia or refrigerants R11, R12 and 134A. These scales measure both pressure and a corresponding temperature scale. Refrigerant scales that measure both pressure and vacuum are common.
还提供了测量真空的仪表。典型的度量单位是汞的汞或毫米。当需要测量压力和真空时，就可以使用复合量表（见图4）。
Figure 4:
一种ccuracy
通常，仪表的准确性越好，需要毕业就越多。通常，不建议使用小于100毫米的尺寸以进行准确±0.5% or better. That’s because the number of required graduations can render the gauge difficult or even impossible to read.
次要表盘毕业通常不超过量规准确性的两倍。例如，100 psi范围仪表仪具有所需精度±0.5% will have minor graduations of 1 psi (refer to Figure 1).
在您需要更好准确性的仪表的情况下，这通常意味着表盘上的毕业更多。Consider getting a dial that’s a larger size to accommodate the measurement increments.
理想情况下，表盘上的中间尺度应为12点钟，或全尺度范围的中间尺度。ASME建议操作压力应为规模的25％至75％，并且量规范围应为工作压力的两倍。
Design Pressure
设计压力是最大的压力,your gauge will experience during your application. This doesn’t mean sustained pressure, either. There can be a surge of pressure when the machine turns on, or surges or pressure spikes can happen at other times during the application.
提防量规杀手呢Pressure gauges can handle 130% to 150% of the range, depending on the range, but if the pressure goes beyond that you will need to get a gauge with a higher range or protect the gauge from inaccuracy issues or possibly overpressure that can cause gauge failure.Both factors are safety issues that should not be ignored.
一种pressure limiting valve（PLV）可以通过关闭进入量规的压力来帮助保护量规免受超压的影响。当过程压力有时可能超过范围的130％至150％时，请考虑使用此附件。
PLV通常是建立在全面的范围the gauge. When the pressure reaches the setpoint of the PLV, pressure into the gauge is shut off, protecting the gauge from overpressure. It will also contain the process media so nothing dangerous leaks out into the environment.
一种t Ashcroft, we publishrupture or burst pressures对于我们的流程计。没有多少其他制造商也这样做。
We don’t like to pressure you, but we have more information.
You should be clearer now on how to decide what range gauge you need for your application to ensure accurate and safe pressure measurements for your application.
如果您想了解更多有关压力计s, feel free to visit our website and view any of our helpful white papers, webinars or guides in our资源中心。
You can also check out some of our other blog posts about gauges:
- How To Identify Your Pressure Gauge and Get the Proper Replacement
- 机械压力表的成本是多少？
- What’s the Right Pressure Instrument Mounting Assembly for Me?
今天随时与我们联系talk to one of our industry expertsand get all your pressure gauge questions answered.
