Total Pressure Gauges

THERMOVAC Transmitters
TTR 91 / TTR 91 S / TTR 96 S
THERMOVAC transmitters are active
sensors (pressure to voltage converters)
using thermal conductivity according
to Pirani.
The further developed THERMOVAC
transmitters have optimized price-toperformance
ratio.
The value of the trigger point can be
switched easily on the analog output
and be shown on the display of the
operating unit.
Advantages to the User
- Rugged sensing cells made of
stainless steel
- Compact design
- Stable measurements within a wide
temperature range
- Highly resistant to overpressures
- Exchangeable sensing cells
- Fast response
- Available with integrated switching
relay (TTR 91 S, TTR 96 S)
65
50
22.2
Typical Applications
- Analytical engineering
- Safety circuits in vacuum systems
- Controlling ionization gauges
- General pressure measurement and
control on systems in the fine and
rough vacuum range
Sensor
The THERMOVAC transmitter has a
Pirani sensing cell equipped with a
tungsten (TTR 91/TTR 91 S) or nickel
(TTR 96 S) filament.
If required, the sensing cells can easily
be aligned to any precisely known
pressure value (atmospheric, “zero”,
reference pressure) by pressing a
button.
Integration of the transmitters in programmable
control systems is facilitated
by the linear characteristic, which
can be defined by entering a simple
equation into the computer. The transmitters
TTR 91 / TTR 91 S / TTR 96 S
are compatible to older TTR models
like TTR 211, TTR 216 S or TTR 90.
Built-in relays allow switching functions
to be performed directly by the transmitter,
without the need of a programmable
control.
70.4
33
10
9
8
Equation Formel
p = 10 0,778 (U(a) - 6,143) mbar
15
DN 16 ISO-KF
DN 16 CF-R
14
115
DN 16 CF-R
29
1/8" NPT
U(a) / Volt
7
6
5
4
3
2
1
0
2 4 68
10 -4 10 -3 10 -2 10 -1 10 0 10 1 10 2 mbar 10 3
Pressure Druck
Dimensional drawing for the
TTR 91 / TTR 91 S / TTR 96 S
Characteristic of the THERMOVAC Transmitters
C16 22
Oerlikon Leybold Vacuum Full Line Catalog