Pacific Northwest PNW 421 Using Manual - page 13
Dial gauge inspection and accuracy
This form can be used with a master gauge testing unit
(Not for use with maximum thermometers)
Dial gauges should be checked for accuracy and overall condition
every year prior to the beginning of canning season. If you use your
dial gauge canner throughout the year, check it at the same time
every year.
DATE:____________________________
CONDITION OF GAUGE:
Good Rusty Broken, cracked
Interior moisture Cover too scratched to read
Comments:__________________________________________
ACCURACY OF DIAL GAUGE: (psi = pounds per square inch)
When MASTER reads 5 psi, YOUR GAUGE reads_____psi.
When MASTER reads 11 psi, YOUR GAUGE reads_____psi.
When MASTER reads 15 psi, YOUR GAUGE reads_____psi.
RECOMMENDATION:
If your gauge reads high or low by two (2) pounds (psi) or less, you
may use it with the following compensation: (check one)
If your gauge reads up to two (2) pounds higher than the
master gauge, you must add the amount of difference to the
required pressure so you donʼt underprocess your food.
For example, if the MASTER gauge reads 11 psi and your
gauge reads 12 psi (1 pound higher than the master gauge),
process at 12 psi when the instructions say 11 psi, or 13 psi
when the instructions say 12 psi, or 7 psi when the instruc-
tions say 6 psi, etc.
If your gauge reads up to two (2) pounds lower than the mas-
ter gauge, you may subtract the same amount it differs from
the required pressure. (In this case, you may also use the
pressure stated in the instructions for added safety.)
For example, if the MASTER gauge reads 11 psi and your
gauge reads 10 psi (1 pound lower than the master gauge),
you may process at 10 psi when the instructions say 11 psi, or
11 psi when the instructions say 12 psi, or 5 psi when the
instructions say 6 psi, etc.
If your gauge reads high or low by more than two (2) pounds, replace.
Note: These recommendations for adjustment are based on information provided
by National Presto Industries, 2002, in instructions for Presto Testing Unit 81288.
Source: National Center for Home Food Preservation, 5/07