What is the reading of the differential pressure gauge?
Thread Content
Method 1: Read the small dial, approximately 0.04 Mpa； Method 2: The red needle reads approximately 0.587 on the large dial, while the black needle reads around 0.56; the difference is about 0.028 ； Which value is more accurate, do you ask?
Of course, the larger grid has a higher resolution. The values for both are the same; it’s just that with the smaller grid you can’t see details as finely, and the errors are greater.
1. First, figure out why a small dial is needed 2. Find out the positions indicated by the red and black hands of the gauge before it is installed. Once you understand the above two points, you will know how to read the values.
First, learn about the working principle of the double-needle, double-tube differential pressure gauge: It consists of two separate measurement systems and indicating devices. The measured pressure is determined through the elastic deformation of the pressure-sensing elements; the displacements that occur at the ends of these elements (bourdon tubes) are amplified via a linkage mechanism. The red pointer and black pointer, fixed to the gear shaft, indicate the measured values on the dial, while the small dial in between shows the difference between the two pressures. Instructions for using a dual-needle differential pressure gauge: 1. The maximum scale on the dial of a dual-needle, dual-tube differential pressure gauge represents the maximum pressure it can withstand. 2. It is recommended that for dual needle and dual tube differential pressure gauges, the ΔP (differential pressure value = P + —P–) be between one-half and one-third of the dial scale value for optimal performance. If it’s too small, it becomes difficult to read the value; this is why reading by subtraction is recommended. 3. The red needle of the dual-needle differential pressure gauge indicates positive pressure (the input pressure is P+) ； The dial needle indicates negative pressure (output pressure P-). The scale on the dial needle can be used to directly read the value by forming an angle α with the red needle (by looking at the scales directly on the dial), or the differential pressure value △P = P + —P– can be calculated by using the value indicated by the dial needle on the dial and the value indicated by the red needle on the dial. 4. The reading on the small dial is the differential pressure; since the angle α remains constant, any difference in readings is due to human error. I’m not sure if you understand this.
Isn’t that a difference of approximately 0.04 MPa?
After switching, it will be normal; there should be no problems.