INSTRUMENT MANUAL
VACUUM GAUGE MODEL MM200
160Phone:(215) 947-2500 fax:(215) 947-7464 e-mail:[email protected] web site:www.televac.com
MM-200_im REV M
Page 49 of 160
TELEVAC
0-10V
OUTPUT OPTIONS
See Section 1000 for curves of voltage-vs-pressure for the outputs listed in Table 4.1.
LINEAR
- This is compatible with linear recorders and linear chart paper. The range of display is limited. Only the
top two decades can be easily read. Below this point the output drops to less than 0.1 volts for a full-scale output of
10 V.
LINEAR PER DECADE
- This output is best used when the 0-10V
output covers a range of several decades such
as 10
-3
to 10
+3
Torr and a "strip chart" recorder with linear paper is being used to record the data. In the example
mentioned, the range covers six (6) decades.
Since the top of any decade (eg. 10 x 10
-3
) is the same as the bottom of the next higher decade, (eg. 1 x 10
-2
),
there are only 9 divisions in a decade. A six decade output, for example, which is linear within each decade can
best be plotted on chart paper with six (6) major divisions and nine (9) minor divisions. This chart paper is non-
standard. To accommodate the use of a standard linear chart paper with 10 major divisions and 10 minor divisions,
the 0-10V
output is made discontinuous between the top of one decade and the bottom of the next higher decade.
With the linear per decade analog output, six decades can be plotted on one standard chart and the value of
vacuum (pressure) can be easily read. The value of the voltage within any decade is equal to the value at the top
of the next lower decade plus a variable adder voltage. For a
1 V/decade output the adder for 5 x 10
-x
would be .5 volts.
LOGARITHMIC
- This output is best used when the 0-10V
output covers a range of several decades such as 10
-3
to 10
+3
Torr and a "data acquisition system" is being used to record the data. In the example mentioned, the range
covers six (6) decades. The output curve (voltage-vs-pressure) is a continuous output from 0- 10 volts (or mV)
covering the entire range with a slope of "X" volts/decade.
2A NON-LINEAR
- This output matches the direct voltage-vs-pressure of the old 2A instrument with a 0- 10 volt
output. This output is best used when a "strip chart" recorder with pre-printed Televac 2A non-linear paper is being
used to record the data.
2C NON-LINEAR
- This output matches the direct voltage-vs-pressure of the old 2C instrument with a 0- 10 volt
output. This output is best used when a "strip chart" recorder with pre-printed Televac 2C non-linear paper is being
used to record the data.
7AC NON-LINEAR
- This output matches the direct voltage-vs-pressure of the old 7AC instrument with a 0- 10 volt
output. This output is best used when a "strip chart" recorder with pre-printed Televac 7AC non-linear paper is
being used to record the data.
7B2 NON-LINEAR
- This output matches the direct voltage-vs-pressure of the old 7B2 instrument with a
0- 10 volt output. This output is best used when a "strip chart" recorder with pre-printed Televac 7B2 non-
linear paper is being used to record the data.
