Instruction Manual
MX4A Active Convection Gauge
The MX4A qualifies as a Safety Extra-Low Voltage (SELV) device. As such, it represents little to no
hazard concerning electrical shock or burns.
Do not substitute parts or modify instrument. Because of the danger onj introducing addi-
tional hazards, do not install substitute parts or perform any unauthorized modifications
to the product. Return the product to Televac for service and repair to ensure that safety
features are maintained. Do not use this product if it has unauthorized modifications.
2
Setup
2.1
Installation
Each MX4A is designed to be used in conjunction with a 4A sensor. Mount the 4A sensor in an upright
position and as close to the area where vacuum measurement is desired. Failure to mount the 4A
sensor in a vertical position will decrease the accuracy of the measurement above 10 Torr. Each 4A
sensor has a key that only allows for the MX4A to mate with the sensor in the proper orientation.
Rotate the MX4A until the correct alignment is obtained and the MX4A is able to slide onto the 4A
sensor. Connect the power connector to the top of the unit and be sure to tighten the screws so that
a firm connection is maintained.
Try to avoid connecting the MX4A to the vacuum chamber by long or narrow piping as this may
affect the accuracy and response time of the unit. Avoid mounting the unit near a heater within the
chamber as this may affect the measurement accuracy. Excessive vibration of the unit may affect
accuracy and decrease the life of the unit. Exposure to oils and other contaminants will decrease the
accuracy and decrease the life of the sensor. Do not expose the unit to corrosive gases.
2.2
Electrical Information
Power connectors and adaptors for use with the MX4A are available for purchase from Televac. Op-
erators wishing to create their own adaptors should refer to the pin out of the MX4A below. Each
connection labeled “Floating” has no connection and should remain so.
Figure 2: MX4A Electrical Connection Information
Pin
Description
1
Analog Output (Ground)
2
RS-485 (-)
3
SP2 NC
4
SP2 NO
5
SP1 Open Drain
6
Floating
7
Floating
8
Supply Voltage
9
Analog Output (0 to 10 V)
10
RS-485 (+)
11
SP2 Com
12
SP1 Source
13
Floating
14
Floating
15
Ground
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tel: +1 215 947 2500
web: frederickscompany.com
mx4a_im rev L
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