SCIENTIFIC INSTRUMENTS 6290 - Option 2, Alarm Levels; Option 3, Density (Edit Density Parameters); Option 1, Calibration Values; Option 4, System (Edit System Parameters)

090-252 Rev A
2-7
2.2.2.3 Option 3, Density (Edit Density Parameters)
Choosing option 3 on the Edit Parameters menu brings up the "Edit Density
Parameters" submenu.
2.2.2.3.1 Option 1, Calibration Values
This option gives access to the calibration values for the density meter.
These include T0, D0, and K. Density is calculated according to the
formula
d = 2( D
0
) ( T / T
0
) ( 1 + K ( T / ( 2T
0
) ) ),
where:
d = Measured density in kg/m
3
(or lb/ ft
3
in the English system),
D
0
= Meter constant in kg/m
3
,
t = Output signal period at density (d), in µs,
T
0
= Output signal period in vacuum, in µs,
T = t – T
0
, and
K = Calibration constant.
The required values are supplied by the density meter manufacturer and
are listed on the configuration worksheet for reference.
2.2.2.3.2 Option 2, Alarm Levels
This option allows the user to edit the density values at which alarms will
be generated. They include the low density limit, the high density limit,
and the density deviation limit. The density deviation limit applies only
when a profile run is made. Each point is compared with the next point;
when the difference in density exceeds this set point, this alarm is
generated.
2.2.2.4 Option 4, System (Edit System Parameters)
Choosing option 4 on the Edit Parameters menu brings up the "Edit System
Parameters" submenu.
2.2.2.4.1 Option 1, General
This option allows the user to set several parameters including Unit ID,
Power Up Action, and Display Units.
The Unit ID is necessary when there is more than one system linked
together on an RS485 communication bus. It allows a host computer to
address each M6290 individually. Communication will not be possible if
each unit is not set with a unique tank I.D.