Pfeiffer Vacuum CMR371 User manual

BG 5138 BEN / A (2012-11)
A PASSION FOR PERFECTION
CMR 371 … CMR 375
Ceramic Capacitance Gauge
Operating Instructions

2BG 5138 BEN / A (2012-11)
Product Identification
In all communications with Pfeiffer Vacuum, please specify the
information given on the product nameplate. For convenient re-
ference copy that information into the space provided below.
Pfeiffer Vacuum, D-35614 Asslar
Typ:
Range:
No:
F-No:
V W; LPS

BG 5138 BEN / A (2012-11) 3
Validity
This document applies to products with the following part num-
bers:
Measurement range
min. (1 V) F.S. (9 V) max. (9.8 V)
Type Part number Flange [mbar]
[Pascal]
[mbar]
[Pascal]
[mbar]
[Pascal]
PT R25 100 ½" tube
PT R25 101 DN 16 ISO-KF
PT R25 102 DN 16 CF-R
CMR 371
PT R25 103 8 VCR®
10-1
101
1000
100'000
1100
110'000
PT R25 110 ½" tube
PT R25 111 DN 16 ISO-KF
PT R25 112 DN 16 CF-R
CMR 372
PT R25 113 8 VCR®
10-2
100
100
10'000
110
11'000
PT R25 120 ½" tube
PT R25 121 DN 16 ISO-KF
PT R25 122 DN 16 CF-R
CMR 373
PT R25 123 8 VCR®
10-3
10-1
10
1'000
11
1'100
PT R25 130 ½" tube
PT R25 131 DN 16 ISO-KF
PT R25 132 DN 16 CF-R
CMR 374
PT R25 133 8 VCR®
10-4
10-2
1
100
1.1
110
PT R25 140 ½" tube
PT R25 141 DN 16 ISO-KF
PT R25 142 DN 16 CF-R
CMR 375
PT R25 143 8 VCR®
10-5
10-3
0.1
10
0.11
11
The part number (No) can be taken from the product nameplate.
If not indicated otherwise in the legends, the illustrations in this
document correspond to CMR 37X gauges with the
DN 16 ISO-KF vacuum connection. They apply to other vacuum
connections by analogy.
We reserve the right to make technical changes without prior
notice. All dimensions in mm.

4BG 5138 BEN / A (2012-11)
Intended Use
The temperature compensated Capacitance Diaphragm Gauges
of the CMR 37X series are intended for absolute pressure
measurement of gases in their respective pressure ranges
(→3).
Functional Principle
A ceramic diaphragm is deflected by pressure. The deflection is
measured capacitively and converted into an analog linear out-
put signal by the digital electronics.
The output signal is independent of the gas type.
Very accurate pressure measurement is achieved by heating the
sensor to a constant temperature of 45°C which results in a com-
pensation of changes in the ambient conditions and a reduced
deposition of process products and by-products in process appli-
cations.
Trademark
VCR®Swagelok Marketing Co.
Patents
EP 1070239 B1, 1040333 B1
US Patents 6528008, 6591687, 7107855, 7140085
Scope of Delivery
1× gauge CMR 37X in clean room packaging
1× pin for adjusting settings via buttons
1× Calibration Test Report
1× Operating Instructions German
1× Operating Instructions English

BG 5138 BEN / A (2012-11) 5
Contents
Product Identification 2
Validity 3
Intended Use 4
Functional Principle 4
Trademark 4
Patents 4
Scope of Delivery 4
1Safety 6
1.1 Symbols Used 6
1.2 Personnel Qualifications 6
1.3 General Safety Instructions 7
1.4 Liability and Warranty 7
2Technical Data 8
3Installation 13
3.1 Vacuum Connection 13
3.2 Power Connection 16
4Operation 18
4.1 Status Indication 18
4.2 Zeroing the Gauge 18
4.2.1 <ZERO>Adjustment 19
4.3 Activating the Factory Setting (Factory Reset) 22
5Deinstallation 23
6Maintenance, Repair 25
7Returning the Product 25
8Disposal 26
Conversion Table 27
ETL Certification 27
EC Declaration of Conformity 28
For cross-references within this document, the symbol (→XY)
is used.

6BG 5138 BEN / A (2012-11)
1 Safety
1.1 Symbols Used
DANGER
Information on preventing any kind of physical injury.
WARNING
Information on preventing extensive equipment and environ-
mental damage.
Caution
Information on correct handling or use. Disregard can lead to
malfunctions or minor equipment damage.
Notice
1.2 Personnel Qualifications
Skilled personnel
All work described in this document may only be carried out by
persons who have suitable technical training and the neces-
sary experience or who have been instructed by the end-user
of the product.

BG 5138 BEN / A (2012-11) 7
1.3 General Safety Instructions
•Adhere to the applicable regulations and take the necessary
precautions for the process media used.
Consider possible reactions with the product materials.
•Adhere to the applicable regulations and take the necessary
precautions for all work you are going to do and consider the
safety instructions in this document.
•Before beginning to work, find out whether any vacuum com-
ponents are contaminated. Adhere to the relevant regulations
and take the necessary precautions when handling contamin-
ated parts.
Communicate the safety instructions to all other users.
1.4 Liability and Warranty
Pfeiffer Vacuum assumes no liability and the warranty becomes
null and void if the end-user or third parties
•disregard the information in this document
•use the product in a non-conforming manner
•make any kind of interventions (modifications, alterations etc.)
on the product
•use the product with accessories not listed in the product
documentation.
The end-user assumes the responsibility in conjunction with the
process media used.
Gauge failures due to contamination or wear and tear are not
covered by the warranty.

8BG 5138 BEN / A (2012-11)
2 Technical Data
Measurement range →"Validity"
Accuracy 1) 0.15% of reading
Temperature effect on zero
PT R25 100 … PT R25 133
PT R25 140 … PT R25 143
0.0025% F.S./ °C
0.005% F.S./ °C
Temperature effect on span 0.01% of reading / °C
Resolution 0.003% F.S.
Gas type dependence none
Output signal analog
(measuring signal)
Voltage range 0 … +11 V
Measuring range +1.0 … +9.8 V
Relationship voltage-pressure linear
Error signal <0.4 V (no supply,
sensor error)
>9.8 V ("overrange")
Output impedance 0 Ω(short-circuit proof)
Loaded impedance >10 kΩ
Response time 2)
PT R25 100 … PT R25 133
PT R25 140 … PT R25 140
30 ms
130 ms
Gauge identification Resistance 13.2 kΩrefer-
enced to supply common
Voltage ≤5 V
1) Non-linearity, hysteresis, repeatability in the calibrated range at
25 °C ambient operating temperature without temperature effects
after operation of 2 h.
2) Increase 10 … 90 % F.S.R.

BG 5138 BEN / A (2012-11) 9
Status relay
closed measurement mode
warning
open no supply voltage
warming up
error
Supply
DANGER
The gauge may only be connected to power sup-
plies, instruments or control devices that conform
to the requirements of a grounded protective extra-
low voltage (SELV) and limited power source
(LPS), Class 2. The connection to the gauge has to
be fused.
Supply voltage
at the gauge
Class 2 / LPS
+14 … +30 VDC
Ripple ≤1 Vpp
Power consumption
while being heated
at operating temperature
≤12 W
≤8 W
The gauge is protected against reverse polarity of the supply
voltage.
Electrical connection Hirschmann compact
connector, type GO 6,
6-pin, pins
Sensor cable 5-pin plus shielding
Cable length
Supply voltage 15 V ≤15 m (0.25 mm²/conductor)
Supply voltage 24 V ≤75 m (0.25 mm²/conductor)
Supply voltage 30 V ≤135 m (0.25 mm²/conductor)
For longer cables, larger conductor cross-sections are required
(Rcable ≤1.0 Ω).

10 BG 5138 BEN / A (2012-11)
Grounding concept →"Power Connection"
Materials exposed to vacuum ceramics (Al2O3≥99.5%),
stainless steel AISI 316L
Internal volume ≤4.2 cm3
Admissible pressure (absolute)
PT R25 100 … PT R25 103
PT R25 110 … PT R25 133
PT R25 140 … PT R25 143
300 kPa
200 kPa
130 kPa
Bursting pressure (absolute) 600 kPa
Admissible temperatures
Storage
Operation
Bakeout (not in operation)
–40 °C … +65 °C
+10 °C … +40 °C
≤110 °C at the flange
Relative humidity ≤80% at temperatures
≤+31 °C decreasing to 50%
at +40°C
Use indoors only, altitude up to
2000 m NN
Degree of protection IP 40

BG 5138 BEN / A (2012-11) 11
Dimensions [mm]
8 VCR
female
DN 16 ISO-KF
82
110.4
DN 16 CF-R
A
D½"
31.5
17.8
13
Weight 837 … 897 g

12 BG 5138 BEN / A (2012-11)
Analog Measuring Signal vs. Pressure
123456789
0.5
100
00.6
0.6
1.0
0.7
0.8
0.9
0.1
0.2
0.3
0.4
1.1
9.8
sensor error
underrange
overrangesensor error
underrange
overrangesensor error
underrange
overrange
sensor error
underrange
overrange
F.S.
Measuring signal U [V]
Pressure p [mbar]
p = (U - 1) × c (F.S.)
mbar Pa Torr
c 0.125 12.5 0.094
Example: Gauge CMR 371 with 1000 mbar F.S.
Measuring signal Uout = 6 V
p = (6 V - 1 V) × 0.125 × 1000 mbar
= 625 mbar

BG 5138 BEN / A (2012-11) 13
3 Installation
WARNING
WARNING: fragile components
The ceramic sensor may be damaged by impacts.
Do not drop the product and prevent shocks and
impacts.
3.1 Vacuum Connection
DANGER
DANGER: overpressure in the vacuum system
>1 bar
Injury caused by released parts and harm caused
by escaping process gases can result if clamps are
opened while the vacuum system is pressurized.
Do not open any clamps while the vacuum system
is pressurized. Use the type clamps which are
suited to overpressure.
DANGER
DANGER: overpressure in the vacuum system
>2.5 bar
KF flange connections with elastomer seals (e.g.
O-rings) cannot withstand such pressures. Process
media can thus leak and possibly damage your
health.
Use O-rings provided with an outer centering ring.

14 BG 5138 BEN / A (2012-11)
DANGER
DANGER: protective ground
Products that are not correctly connected to ground
can be extremely hazardous in the event of a fault.
Electrically connect the gauge to the grounded
vacuum chamber. This connection must conform to
the requirements of a protective connection ac-
cording to EN 61010:
•CF and VCR flanges fulfill this requirement.
•For gauges with a KF flange, use a conductive
metallic clamping ring.
•For gauges with a ½" tube, take appropriate
measures to fulfill this requirement.
Caution
Caution: vacuum component
Dirt and damages impair the function of the vac-
uum component.
When handling vacuum components, take appro-
priate measures to ensure cleanliness and prevent
damages.
Caution
Caution: dirt sensitive area
Touching the product or parts thereof with bare
hands increases the desorption rate.
Always wear clean, lint-free gloves and use clean
tools when working in this area.

BG 5138 BEN / A (2012-11) 15
Mount the gauge so that no vibrations occur. The gauge
may be mounted in any orientation. To keep conden-
sates and particles from getting into the measuring
chamber preferably choose a horizontal to upright posi-
tion. If adjustment should be possible after the gauge
has been installed, be sure to install it so that the but-
tons can be accessed with a pin (→18).
Remove the protective lid and connect the product to the vac-
uum system.
Seal with centering ring
Protective lid
Clamp
Keep the protective lid.

16 BG 5138 BEN / A (2012-11)
3.2 Power Connection
Make sure the vacuum connection is properly made
(→13).
DANGER
The gauge may only be connected to power sup-
plies, instruments or control devices that conform
to the requirements of a grounded protective extra-
low voltage (SELV) and limited power source
(LPS), Class 2. The connection to the gauge has to
be fused.
Ground loops, differences of potential, or EMC problems
may affect the measurement signal. For optimum signal
quality, please do observe the following notes:
•Use an overall metal braided shielded cable. The
connector must have a metal case.
•Connect the cable shield to ground at one side via the
connector case. Make sure the connector case has
direct contact to the cable's shield on its whole cir-
cumference. Do not connect the other side of the
shield.
•Connect the supply common with protective ground
directly at the power supply.
•Use differential measurement input (signal common
and supply common conducted separately).
•Potential difference between supply common and
housing ≤18 V (overvoltage protection).

BG 5138 BEN / A (2012-11) 17
If no sensor cable is available, make one according to the
following diagram (cable length and conductor cross-
sections →9).
Electrical connection
Pin 1 Identification
Pin 2 Signal output (measuring signal)
Pin 3 Signal common
Pin 4 Supply
Pin 5 Supply common
Pin 6 Screening
Connector,
soldering side
2
5
31
6
4
–
+
–
+
2
3
1
4
5
1MΩ
100nF
18 V
6
13K2
Connect the sensor cable to the gauge and secure it using
the lock screw.
Connect the sensor cable to the controller.

18 BG 5138 BEN / A (2012-11)
4 Operation
Put the gauge into operation.
A warm-up time of at least ½ hour should be allowed; for exact
pressure measurements a warm-up time of at least 2 hours is
required.
4.1 Status Indication
STATUS ZERO
For factory
setting only
LED LED status Meaning
<STATUS> off no supply voltage
lit solid green measurement mode
blinking green
short blinks
long blinks
warning, over/underrange
warming up
lit solid red error
4.2 Zeroing the Gauge
The gauge is factory calibrated while "standing upright"
(→"Calibration Test Report").
We recommend performing a zero adjustment, when the
gauge is operated for the first time.
Due to long time operation or contamination, a zero drift could
occur and zero adjustment may become necessary.

BG 5138 BEN / A (2012-11) 19
For adjusting the zero, operate the gauge under the same con-
stant ambient conditions and in the same mounting orientation
as normally.
The output signal (measuring signal) is depending on the moun-
ting orientation. The signal difference between the vertical and
horizontal mounting orientation is:
F.S. ΔU / 90°
1000 Torr/mbar ≈2 mV
100 Torr/mbar ≈10 mV
10 Torr/mbar ≈50 mV
1 Torr/mbar ≈300 mV
0.1 Torr/mbar ≈1.8 V
If the gauge is operated via a controller, the zero of the
whole measuring system has to be adjusted on the
controller: first, adjust the zero of the gauge and then,
the zero of the controller.
4.2.1 <ZERO>Adjustment
While the gauge is being heated and/or under atmos-
pheric pressure, the zeroing function is locked in order
for operating errors to be prevented.
Evacuate the gauge to a pressure according to the table
below:
F.S.
Recommended final pressure for
zero adjustment
1100 mbar
110 mbar
11 mbar
1.1 mbar
0.11 mbar
<6.65×100Pa
<6.65×10-1 Pa
<6.65×10-2 Pa
<6.65×10-3 Pa
<6.65×10-4 Pa
<5×10-2 mbar
<5×10-3 mbar
<5×10-4 mbar
<5×10-5 mbar
<5×10-6 mbar
If the final pressure is too high for zero adjustment (>25%
of the F.S.), the zero cannot be reached and the
<STATUS> LED blinks green. If this is the case, activate
the factory setting and adjust the zero again (→22).

20 BG 5138 BEN / A (2012-11)
Operate the gauge for at least 1 hour (until the signal is
stable).
Briefly press the <ZERO> button with a pin (max.
ø1.1 mm). The zero adjustment runs automatically. The
<STATUS> LED blinks until the adjustment (duration ≤8 s)
is completed.
max. ø1.1 mm
Press the button briefly
After zero adjustment the gauge automatically returns to
measurement mode. The <STATUS> LED lit.
The <STATUS> LED blinks green if
•the signal output is negative (< -20 mV) when the final pres-
sure has been attained
•the zero adjustment has failed.
4.2.2 <ZERO>Adjustment with Ramp Function
The ramp function allows to adjust the zero at a known reference
pressure within the measurement range of the gauge.