Teledyne 2002 instruction manual UNITS Mode, Default Calibration Restoration

	TABLE 1
Gas Mode	Gas

Displayed Number 0.0………………………..Nitrogen

0.1…………………...……..Argon

0.2…………………...…….Helium

0.3………………...…Water Vapor

0.4………………....……..Custom

light will now flash. Use the UP and DOWN switches to individually select the desired code. Return the Model 2002 to the RUN mode.

Note: Factory calibration is performed using nitrogen only. Displayed pressure measurements using other gases are based on established gas thermal conductivity data.

3.6.UNITS Mode

The Model 2002 can display the measured pressure in different pressure units, Torr, mbar or Pascal. To switch between these units press the MODE switch until the UNITS field is lit. Press the UP and DOWN switches simultaneously. The UNITS light will now flash. Use the UP and DOWN switches individually to select the desired unit.

The unit’s mode is also used to display the RS-485 address, (see section 6.3).

A commonly used unit is mTorr which is also known as the micron (short for micron of Hg). One Torr is equal to 1000 mTorr. The table below illustrates how to interpret the display in mTorr.

mTorr Conversions
1 mTorr	=	1.00 x 10-3	Torr
10 mTorr	=	1.00 x 10-2	Torr
100 mTorr	=	1.00 x 10-1	Torr

Table 2 gives conversion factors for the most often used pressure units.

TABLE 2

	Torr	atm	mbar	Pa	psi
Torr (mm Hg)	1	1.32x10-3	1.3332	133.32	1.934x10-2
mTorr (micron Hg)	10-3	1.32x10-6	0.00133	0.13332	1.934x10-5
atm (athmosphere)	760	1	1013.23	1.013x10	14.7
mbar (millibar)	0.75	9.869x10-4	1	100	1.45x10-2
Pa	7.5x10-3	9.869x10-6	0.01	1	1.45x10-4
psi (lb/in)	51.72	6.805x10-2	68.953	6895.3	1

Default Calibration Restoration

The UNITS mode is also used to load default calibration data in rare cases where the transducer EEPROM has become corrupted. The default calibration data should be considered an approximate calibration because the values entered in the controller’s software are based on averaged data collected over a large number of transducers. While this type of calibration download is not a true calibration, it does allow the user to return the unit to a reasonable status from which a full calibration can be easily performed.

Model 2002 Vacuum Gauge Page 13 of 37