Answer / carl_ellis

A bubbler system uses a pneumatic differential relay as a constant flow regulator.  Most bubbler systems include a variable area flowmeter, a rotameter, to indicate the air/gas flow rate and a needle valve for adjusting the flowrate.  

Typical air/gas flowrates for bubblers are 8-30 cc/s (1 to 4 SCFH), a flow rate suitable to create a constant stream of bubbles from the dip tube.

The only 'calibration' of the pressure transmitter in a bubbler system is setting the range of the transmitter's 4-20mA output with a zero-to-span range that takes into account the maximum liquid column head pressure that the transmitter will 'see', which takes into account the specific gravity of the liquid.

Conversion to physical level units (accounting for specific gravity) is done in the receiver (indicator/PLC/DCS/PAC/controller).

Carl Ellis
Measure First

What is the relationship between GAIN and PROPORTIONAL BAND.

1 Answers   Kharafi National, Sabic,

---

what are the different types of terminal lugs used for wiring termination?

5 Answers   Yokogawa,

---

Why humidity limit is 30 to 55 % for raw material storage?

1 Answers  

---

how do u calibrate the vacuum transmitter if it shows more reading

0 Answers  

---

What is the meaning of Dry contact and Wet Contact related to to sensors?

5 Answers   Emerson, Google,

---

What is the difference between fiber optic cable & Ethernet cable

2 Answers   BEMCO, CCC, Pidilite,

---

why using 4-20ma not using 0-20or why not using 1- 20ma???????

7 Answers  

---

what is performance test.need defination

0 Answers   Takreer,

---

Instrumentation symbols interpration, P& ID, Logic diagram analysis, Electrical drawing analysis.

0 Answers   CCIE,

---

uses of profibus?

1 Answers  

---

how we can check level probe and controller

2 Answers  

---

A pressure transmitter with a range of 0-100 bar.The accuracy of the instrument is 1% of upper range value? The pressure indicating transmitter is showing the system pressure is 50 bar. b. When you include the error, what is the minimum possible pressure in our fuel gas system? i. 49.5 bar ii. 49 bar iii. 1 bar iv. 0.5 bar We want to change the filter cartridge. We must depressure the fuel gas system. c. After we depressure the system in preparation for maintenance, the transmitter displays a pressure of +0.1 bar. At this time, what is the possible range of pressures in our fuel system? i. +0.099 to +0.101 bar ii. 0 to +0.2 bar iii. -0.1 to +0.3 bar iv. -0.9 to +1.1 bar

3 Answers  

---