Campbell Scientific CR9000X Measurement and Control System - Manual (Page 97)

Section 3. CR9000X Measurement Details
Settling time for a particular sensor and cable can be measured with the
CR9000x. Programming a series of measurements with increasing settling
times will yield data that indicates at what settling time a further increase
results in negligible change in the measured voltage. The programmed
settling time at this point indicates the true settling time for the sensor and
cable combination.
Example 3.1.3-1 presents CRBASIC code to help determine settling time
for a pressure transducer with 200 feet of cable. The code consists of a
series of full-bridge measurements (BrFull ()) with increasing settling
times. The pressure transducer is placed in steady-state conditions so
changes in measured voltage are attributable to settling time rather than
changes in the measured pressure.
EXAMPLE 3.1.3-1. CRBASIC Code: Measuring Settling Time
'CR9000X Series Datalogger
'Program to measure the settling time of a sensor
'measured with a differential voltage measurement
Public PT(20)
'Variable to hold the measurements
DataTable (Settle,True,100)
Sample
(20,PT(),IEEE4)
EndTable
BeginProg
Scan
(1,Sec,3,0)
BrFull (PT(1),1,mV7_5,4,1,5,1,1,5000,True,True,100,250,1.0,0)
BrFull (PT(2),1,mV7_5,4,1,5,1,1,5000,True,True,200,250,1.0,0)
BrFull (PT(3),1,mV7_5,4,1,5,1,1,5000,True,True,300,250,1.0,0)
BrFull (PT(4),1,mV7_5,4,1,5,1,1,5000,True,True,400,250,1.0,0)
BrFull (PT(5),1,mV7_5,4,1,5,1,1,5000,True,True,500,250,1.0,0)
BrFull (PT(6),1,mV7_5,4,1,5,1,1,5000,True,True,600,250,1.0,0)
BrFull (PT(7),1,mV7_5,4,1,5,1,1,5000,True,True,700,250,1.0,0)
BrFull (PT(8),1,mV7_5,4,1,5,1,1,5000,True,True,800,250,1.0,0)
BrFull (PT(9),1,mV7_5,4,1,5,1,1,5000,True,True,900,250,1.0,0)
BrFull (PT(10),1,mV7_5,4,1,5,1,1,5000,True,True,1000,250,1.0,0)
BrFull (PT(11),1,mV7_5,4,1,5,1,1,5000,True,True,1100,250,1.0,0)
BrFull (PT(12),1,mV7_5,4,1,5,1,1,5000,True,True,1200,250,1.0,0)
BrFull (PT(13),1,mV7_5,4,1,5,1,1,5000,True,True,1300,250,1.0,0)
BrFull (PT(14),1,mV7_5,4,1,5,1,1,5000,True,True,1400,250,1.0,0)
BrFull (PT(15),1,mV7_5,4,1,5,1,1,5000,True,True,1500,250,1.0,0)
BrFull (PT(16),1,mV7_5,4,1,5,1,1,5000,True,True,1600,250,1.0,0)
BrFull (PT(17),1,mV7_5,4,1,5,1,1,5000,True,True,1700,250,1.0,0)
BrFull (PT(18),1,mV7_5,4,1,5,1,1,5000,True,True,1800,250,1.0,0)
BrFull (PT(19),1,mV7_5,4,1,5,1,1,5000,True,True,1900,250,1.0,0)
BrFull (PT(20),1,mV7_5,4,1,5,1,1,5000,True,True,2000,250,1.0,0)
CallTable Settle
NextScan
EndProg
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