Sealey TA090 User Manual

Page 14

Original Language Version

TA090 Issue No.1 25/10/12

16. MEASUREMENT USING STATISTICS

Limits can be entered in DIRECT and a selected GROUP memory at any time, i.e. before, during and

after a series of measurements. There is practical use for limits. Any reading which falls outside the

set tolerance limits will be registered by a warning indication:

H: reading above HI limit

L: reading below LO limit

Please set the limit values using the MENU system.

15. LIMIT FUNCTION

16.1 The gauge calculates statistics from a maximum of 80 readings(GRO1 to GRO4: in total, a

maximum of 320 readings can be stored). In addition, readings can’t be stored in DIR mode, but it

can calculate statistics as GRO1~GRO4. When power off or changing Work Mode(see MENU system

for details), the DIR statistics will be lost. The following statistical values are calculated:

NO.: number of readings in Work Mode

AVG: average value

Sdev. : standard deviation

16.2 Statistical Terms

Average value

The sum of readings divided by the number of readings.

Standard Deviation(Sdev.)

The sample standard deviation is a statistic that measures how “spread out” the sample is around the

sample mean. The sample standard deviation increases with increasing spread out. The standard

deviation of a set of numbers is the root mean square of the variance S²

The variance of a list is the square of the standard deviation of the list, that is, the average of the

squares of the deviations of the numbers in the list from their mean divided by the(number of

readings -1 )

Variance

Standard deviation

NOTE: Deletion must take place immediately after a false or erratic reading has been taken. See the

Delete function in MENU system.

16.3 Storage Capacity Overflow

In GROUP mode, If the storage capacity is exceeded, statistics will not be updated, although

measurement can continue. If the memory is full, subsequent readings will be omitted from the

statistics. In this case the word “FULL” will be shown on the LCD in single measuring mode.

In DIRECT mode, if the memory is full. The newest reading will replace the oldest reading. And the

statistics will be updated.