Answer / sam

a Pressure switch is just a small diaphragm that moves as
the pressure increases. This diaphragm is pushing a small
pin upwards and the pin is pushing a micro switch to close.
Obviously if the pressure decreases again, the pin goes down
and the switch will open again. So based on this information
it is easy to see that you just need to supply pressure to
this diaphragm with a hand pump, put your multimeter on the
switch contact in order to see when the switch open or
closes and and make the adjustment on the switch until it
switches at the point where you need it to switch. The
adjustment is normally in the form of a spring.
Increasing or decreasing the tension on this spring will
change how high or low pressure is needed to move the diaphragm.
The only thing that you need to remember when working on
pressure switches, is that if you want to calibrate the
switch as a pressure switch low you need to pump the switch
up higher than your required switching point and then
decreases the pressure slowly until the switch changes
state. The same if you want to use it as a pressure switch
high, you then need to start with a low pressure and
increase your pressure slowly until the switch changes state.
Good luck

who discoverd ohms law?

3 Answers   HPCL,

---

What is the difference between antisurge

1 Answers  

---

i am preparing for BARC ,so plz mail me how to prepare for BARC. ALSO IF POSIBLE SOME RELATED QUESTIONS. MY MAIL ID IS khushi_4uall2003@yahoo.co.in

0 Answers  

---

A differential pressure transmitter is configured to measure the height of an open tank : height 10m and dia 5m. Suppose this same transmitter is shifted to another open tank : height 10m and dia 4m. What will be the %error in measurement? how?

3 Answers   McCoy Engineering,

---

Why is the length of cable layyed from RTD to temp. Transmitter should be minimum? Why does heating effect takes place in their?

1 Answers   Process Control Technologies,

---

If i have 4 Allen Bradely make RS logix 5000 PLC and for viewing that we are using 4 RS view SCADA for 4 different packages. Now, I will want to view two packages on only one SCADA. Then how i will do it?

0 Answers   Essar, Reliance,

---

WHAT IS THE DIFFERENCE B/W PLC and DCS

10 Answers   Bhel,

---

If mVolts can drop by resistance of wire as compare to mA, then how thermocouple mV reaches in CCR as accurate value?

7 Answers  

---

what is cavitation in control valve? & how we can avoid it?

1 Answers   Forbes Marshall, Reliance,

---

1. What means HART communicator / where it is used / how to use it? 2. Types of Thermocouples and its temperature ranges / output of thermocouple? 3. Types of RTDs and its temperature ranges / output of RTD? 4. Idea about Temperature Transmitters? 5. Difference between Analog and Digital signals? 6. Difference between “2 wire” and “4 wire” system / instruments? 7. Difference between “Potential” and “Potential free” contact? 8. Types of flow meters / transmitters? 9. Types of level transmitters? 10. Difference between “Power/Control” cable and “Instrument” cable? 11. What means “shield” and “screen” in cables / how it is useful? 12. Draw a schematic of closed loop circuit of flow / level / pressure / temperature? 13. Idea about calibration of Control valve / positioned / I/P? 14. How to bypass a digital/analog signal in PLC/DCS by hardwire and software?

6 Answers   JSL,

---

What is the difference between mmwc and mmwg?

0 Answers  

---

I want to apply for the universities in US,but i got the GRE score of (650+300=950)TOEFL 69/120.Is this score sufficient for applying universities please i am married i need to go to US because my husband didn't get H1 yet.please send me suggestion

0 Answers  

---