Inst ToolsInst ToolsInst Tools
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Search
  • Books
  • Software
  • Projects
  • Process
  • Tools
  • Basics
  • Formula
  • Power Plant
  • Root Cause Analysis
  • Electrical Basics
  • Animation
  • Standards
  • 4-20 mA Course
  • Siemens PLC Course
Reading: pH Monitoring System Triggers an Alarm
Share
Notification Show More
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • Design
  • PLC
  • Interview
  • Control System
Search
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Analyzers > pH Monitoring System Triggers an Alarm

pH Monitoring System Triggers an Alarm

This pH monitoring system triggers an alarm if the pH value of the process water in the neutralization tank drifts past trip values.

Last updated: February 15, 2022 9:41 am
Editorial Staff
Analyzers Practical Questions
No Comments
Share
4 Min Read
SHARE

This pH monitoring system triggers an alarm if the pH value of the process water in the neutralization tank drifts past either of two thresholds (trip) values:

pH Monitoring System

pH Monitoring System Triggers an Alarm

Answer the following questions about this pH alarm system:

1. If a wire breaks loose at TB56-4, creating an “open” fault in the loop circuit, determine what will happen at the alarm unit (AAH, AAL-41) and also where you would expect to measure voltage in the loop circuit and where you would expect to measure no voltage in the loop circuit.

2. If breaker #25 in panel L4 suddenly trips, what will happen in this system? Will an operator still be able to read the pH value of the water in the neutralization tank?

3. If a fire breaks out near the conduit through which cable 52 runs, causing the plastic insulation around the conductors of cable 52 to melt and consequently causing those conductors to short together, what will happen in this system?

Where would you expect to measure voltage in the loop circuit, and where would you expect to measure no voltage in the loop circuit?

Where would you expect to measure current in the loop circuit, and where would you expect to measure no current in the loop circuit?

4. Calculate the loop current value when the pH measures 6.8 inside the neutralization tank.

5. For those who have studied pH measurement, explain why pH “neutralization” is an important control process in the industry.

6. How can we tell from this diagram whether the 4-20 mA output of transmitter AIT-41 is active or passive (i.e. sourcing or sinking)?

Answers:

If a wire breaks loose at TB56-4, creating an “open” fault in the loop circuit, determine what will happen at the alarm unit (AAH, AAL-41) and also where you would expect to measure voltage in the loop circuit and where you would expect to measure no voltage in the loop circuit. The AAL would trip (but not the AAH), and we would expect to measure voltage between the wires of cable 52 but not between the wires of cable 30.

If a fire breaks out near the conduit through which cable 52 runs, causing the conductors inside cable 52 to short together, what will happen in this system? Where would you expect to measure voltage in the loop circuit, and where would you expect to measure no voltage in the loop circuit? Where would you expect to measure current in the loop circuit, and where would you expect to measure no current in the loop circuit?

The AAL would trip (but not the AAH), and we would expect to measure no voltage anywhere in the loop circuit. However, we would still have current at the terminals of the AIT-41 transmitter (although no current to the right of the short).

Share your answers with us through the below comments section.

Read Next:

  • Pressure Actuated Questions
  • Which Instrument is at Fault?
  • PLC Pushbutton Switches
  • Identify Spool Valve Symbols
  • Analytical Process Control Question

Credits: Tony R. Kuphaldt

Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address
You've successfully subscribed !

Continue Reading

Process Control High Level Alarm Fault Analysis
Simple Pressure Repeater
Determine the functions of Pressure Switches ?
How Do You Connect the Differential Pressure Gauge at the Filter?
Define Normal Status for each of the Process Switch
Indentify Faults in Simple Lamp Circuit including Failed Wires
Share This Article
Facebook Whatsapp Whatsapp LinkedIn Copy Link
Share
Leave a Comment

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Stay Connected

128.3kFollowersLike
69.1kFollowersFollow
210kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

Liquid Level Switch Control Logic
Signal Strength of Guided-wave Radar Level Instrument
Kiln Inlet Gas Analyzer
What is Infrared Flue Gas Analyzer? – Working Principle
pH Analyzer Do’s and Don’ts
Conductivity Analyzers Interview Questions & Answers
Air Compressor Control Circuit Problem
How to Draw a Schematic Diagram ?

Keep Learning

Calculate Temperature of RTD

Calculate Temperature of RTD

Calculate Temperature of Four Wire RTD

Calculate the Temperature of 4 Wire RTD

Oxygen Analyzer Principle

Oxygen Analyzer Working Principle

Manometer with two different liquids

Calculate the Height of Glycerine

Steam flow to the heat exchanger

Analytical Process Control Question

Drum Level differential pressure transmitter

Calculate Differential Pressure Sensed by Level Transmitter

Flapper nozzle system

Flapper Nozzle Questions

Pneumatic Amplifying Relay

Determine Effect of Each Fault for Pneumatic Force-balance System

Learn More

DC Circuits Multiple Choice Questions

DC Circuits Multiple Choice Questions

PID Controller Tuning

How to tune a PID Controller ?

What is electrical transformer

Transformer Impedance Ratio

Arc Fault Breaker (AFB) Electrical Problem Solved

Premature Arc Fault Breaker Failures

Power Electronics Objective Questions

PWM Inverters Objective Questions

Magnetic Tape Recorder Principle

What is Magnetic Tape Recorder ?

Antifriction bearings (AFB) Problems

Antifriction bearings (AFB) Problems and Delays Plant Restarts

Digital Electronics MCQ

Digital Integrated Circuits Objective Questions – Part 1

Menu

  • About
  • Privacy Policy
  • Copyright

Quick Links

  • Learn PLC
  • Helping Hand
  • Part Time Job

YouTube Subscribe

Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Welcome Back!

Sign in to your account

Username or Email Address
Password

Lost your password?