Flintec FAA-24 - Manual (Page 4)

FLINTEC
PAGE 4 OF 4
5. CALIBRATION PROCEDURE
• SWITCH ON THE, CARD AT LEAST 10 MINUTES BEFORE CALIBRATION
• THE TRIMMERS SAFEGUARDED WITH LAQUER MAY NOT BE ADJUSTED!
1. EMPTY THE SCALE AND CALIBRATE THE TARE TRIMMER TO OBTAIN AN
OUTPUT OF 4.00 MA(0.00 MA)
2. LOAD THE SAMPLE WEIGHT AND CALIBRATE THE SPAN TRIMMER TO OBTAIN
A CURRENT OUTPUT CORRESPONDING TO THE SAMPLE WEIGHT.
FOR EXAMPLE(OUTPUT 4-20 MA): WITH A CELL OF 500 KG AND A SAMPLE
WEIGHT OF 250 KG (I.E. 50% OF CAPACITY) THE TRIMMER MUST BE
CALIBRATED TO OBTAIN AN OUTPUT OF 12MA.
THE VALUE OF 12mA IS ARRIVED AT AS FOLLOWS:
THE SPAN OF THE 4-20mA OUTPUT IS 16mA, 50% OF 16mA IS 8mA, WHICH
ADDED TO THE OFFSET OF 4mA gives 12 mA,
IN SYNTHESIS 12 =(16 X 0.5)+ 4. IF THE SAMPLE WEIGHT IS
100Kg(I.E. 20%) THE OUTPUT IS OUT =(16 X 0.2)+ 4 = 7.2
3. EMPTY THE SCALEPAN AND,IF NECESSARY,RECALIBRATE THE OUTPUT WITH
THE ZERO TRIMMER. RECHECK AND RECALIBRATE THE OUTPUT BY MEANS
OF THE SPAN TRIMMER AND THE RELEVANT SAMPLE WEIGHT.
4. CHECK LINEARITY OF THE READING WITH A KNOWN AVERAGE WEIGHT.