bench calibration of instruments using process line

a. prepare the instruments or the table needed in calibratoin
b.isolation of main block valve high and low side
c.close all the low side of 3 valve manifold.then close the high side
c.open the equalizing valve
d.open the vent screw and of both measuring chamber
e.purge with air both measuring chamber so that the air will trap then pully close the equalizing valve

f.install back the drain valve and install host fittings to high side in both measuring chamber.
g.andkeep the low side measurign chambers open to atmosphere
h.connect plastic  host while the other precision manometer to the hand pump.
then pressurize for leak test if hav leak repair then disconnect the one side by the transmitter then connect to fluke 87 and 250 ohms in a series connection
also connect handheld termial probe to the transmitter
then the fluke 97 must be in the MA setting before enregizing then do the calibration of 5 points
after calibration pull out the host fittings and put back the all series and also connect the wire to the transmitter
open the main isolation valve then open the high side
after open the equalizing valve then open the unit screw slowly so that the trap air will be drain to the atmosphere also do the other side close the equalizing valve
after that fully open the low side and the transmitter is online.

draw and explain the calibration procedure of smart temperature xmitter,sensor is thermocouple

a.prepare calibration data sheets, and technical manual of the xmitter for calibration
b.prepare test equipments and accs needed
c.connect compensating cable to the input side of the temperature transmitter
red color wire must be connected to the negative - terminal and yellow wire connect to the + terminal.The other ends connect to a standard simulator(calibrating instruments) yokogawa 2553 DC current voltage standard transmation 1045.
d. connect power supply 24 vdc, its + terminal connect to the other end of the 250 ohms resistor precision whle the other end to the + terminal of the transmitter, The -terminal of the power supply will be connected to the - probe of the fluke 87 and its + probe will be connected the probe of HHT to the terminals of the x mitter (HHT probe has no polarity)

e.power "on" both the power supply and the HHT
f.check the configuration of the xmitter, If not yet configured provide datas fro down loading and configure ncluding its range
g.if in case the x mitter has been configured, get the range and do the 5 points datas for the calibration, get the ambient temp where you are doing the calibration and know the equivalent MV thru its standard temp convection table.
h.get the equivalent MV signal of the 5 points datas and minus the ambient MV signal to the 5 points MV signals. The remaining Mv will your input signal to the x mitter.
i.send MV signal fhru the calibrator from 0.25,50,75 and 100 of the range and its corresponding 4 to 20 MA output.Then decreasing signal from 100,75,50,25 and 0 % of its range. Record the datas of the calibration data sheet under the as found. If in case the output signal did not match to the desired value or accuracy is not satisfied, then adjustments are to be made.
j.thru the hht adjust zero and span until all readings are Ok or within the accuracy limit.again do the 5 points for both increasing and decreasing signals. if all the results are within tolerance base on its accuracy list themn the calibration is complete.So these datas will be our as corrected or as left. compete the calibration data sheet and provide calibration sticker to the xmitter, shut off thepower and disconnect all the wirings.
k. housekeeping.

bench calibration of d/p transmitter

test equipments needed
. digital mutimiter fluke 87
.variable dc power supply
.pressure calibrator/hand pump fluke 718
.precision test gauge
.hard communicator model 375
resistor 250 ohms
ss fittings--- 1/4 " OD NPT male connector
.tee piece---1/4 " OD
set of ferrule and fittings
plastic tube high pressure

procedures:
1. prepare calibration data sheets/technical manuals of transmitter for calibration
2.set the differential pressure transmitter into the bench calibration stand
3.connect  1/4 " OD NPT fitting to high pressure side of d/p transmitter with plastic tube fitted to the end fo 1/4 " OD straight connector including tee piece fittings to the other end whre precision test gauges is connected.
4.connect plastic tube end fittings to the output of pressure calibrator fluke 718
5.connect power supply 24 VDC to the transmitter terminal block positive and negative terminals with a 250 ohms resistor connected in series between powersupply and trasnmitter negative or anyone.
6.connect the hart communicator model 375 pareallel negative positive lines
7/power on 24 VDC power supply and also the hart communicator
8 check cthe configration of the transmitter. if not yet configured, make ready with you the data to download and configure the transmitter
9 after downloading data, check zero of the transmitter with open vent on high side. if zero is ok, close vent and start increasing pressure equivalent to 1,25,50,75,100 of the assigned range with corresponding output readings.
10.decrease the actuating pressure to 100,75,50,25,0 of the assigned ranges.records the corresponding readings.
11. if not ok, repeat steps 9 to 10 and appropriate adustments shallbemade until satisfied accuracy is obtained.
12.ifspan is not ok, adjust span with corresponding max input and output readings, repteat steps 9 and 10 until satisfied
13.the percent erros calculated of the above checked shall not exceed satisfied accuracy of the assigned ranges.
14.fill up calibration reports forms.