Answer Posted / carl_ellis
Calibrating a point level switch
Contact level switches detect the presence or absence of
the medium, whether solid or liquid, by direct contact with
the medium. The switch output for most devices is an
on/off binary signal that reflects the presence or absence
of the medium. Some level switches use a 4-20mA output
that does not modulate, the current signal is either 4mA or
20mA, depending its detection state.
Most level switches offer some form of sensitivity
adjustment (depends on the technology) and some have an on-
delay or off-delay adjustment of the output relay trip,
used to avoid nuisance trips.
Calibration consists of
- testing whether the switch output changes state when the
presence or absence of the medium is changed and adjusting
the sensitivity setting for the specific medium used with
the switch.
- whether the on-delay and off-delay settings comply with
the requirements of the installed application
Depending on the technology, there might be sensitivity
adjustments or on-delay or off-delay adjustments, which are
specific to the installed application, and a calibration
would cover.
A non-contact level switch, like Siemen ultrasonic ULS200,
can be tested in place by comparing the reading with a
physical distance measurement (tape measurement) or out-of-
process by shooting against a solid target and measuring
the distance to check the trip and reset setpoints.
Carl Ellis
Measure First
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
What is the use of gauge?
1- Explain about HPM 2- What is the FSC and explain the configuration of FSC 3- explain the complete loop of vibration, how it works (field to control room) 4- What is the use of proxymitter? 5- During job your partner effected with H2S then what you have to do. 6- what type of gland packing uses when valve glind is leaking.
DEAR SIR/MADAM MY NAME IS ARKAPROVA BHATTACHARYYA.I AM A FRESHER INSTRUMENTATION ENGINEER.CAN YOU PLEASE SEND SOME QUESTION PAPERS OF GRADUATE ENGINEER TRAINEE EXAM OF DVC(DAMODAR VALLY CORPORATION).MY EMAIL IDs ARE arka_aec@rediffmail.com.
How to Calibrate Vortex Flow transmitter in field
how do calibrate the valves.. with clear manual
we are using centum vp as monitoring with Dell precision work station T3600 but some times PC(s) are restarted automatically . how we can solve this problem? thanks
State some of balance principle’ advantages?
Why do we have earthing cable in branch cable and shield in the same cable?
What is the difference between conductive lined pipe and conductive unlined pipe? Why do we see that?
What is the reason PT speed not incresed in gas turbine?
What is the GK Value in Flowmeter?
any questions on motor and energy conversions machines?
How to calculate P,I&D value in PID controller ?
1. For Steam drum level signal, why do we compensate with drum pressure signal? 2.For main steam Flow signal is comensated with main steam temperature signal and main steam pressure signal why?
ORP sensor working principle?