TELEVAC MX7M Instruction Manual

Instruction Manual The Fredericks Company - Televac 2400 Philmont Avenue Huntingdon Valley, PA 19006 email: [email protected] tel: +1 215 947 2500 fax: +1 215 947 7464 ...

Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.4 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.5 Safety Information . . . . . . . . . . . ...

1 Introduction 1.1 Disclaimer All information in this manual is subject to change without notice. The Fredericks Company assumes no responsibility for inaccuracies in product specifications or any liability arising from product use. Please contact Televac at [email protected] or call +1 215-947-2500 with comments or questions. 1.2 Description The MX7M is cold cathode ionization gauge with a measurement range of 5×10−11 Torr to 1×10−2 Torr. It utilizes a Televac cold cathode ionization sensor in the inverted magnetron configuration with part numbers 2-2183-KF25 (KF25 flange version), 2-2183-KF40 (KF40 ...

1.4 Dimensions Figure 1: MX7M Dimensional Drawing email: [email protected] tel: +1 215 947 2500 web: frederickscompany.com mx7m_im rev C 3 of 23 ...

1.5 Safety Information START BY READING THESE IMPORTANT SAFETY INSTRUCTIONS AND NOTES In these instructions the word “product” refers to the MX7M and all of its approved parts and acces- sories. NOTE: These instructions do not and cannot provide for every contingency that may arise in connection with the installation, operation, or maintenance of this product. Should you require further assistance, please contact Televac at the email address found in the footer of this manual. This product has been designed and tested to offer reasonably safe service provided in it is installed, operated and serviced in strict a ...

1.6 Quick Start Guide 1.6.1 Check what you’ve received Compare what you’ve received to your purchase order. 1.6.2 Safety Instructions Review all safety instructions outlined in Section 2 1.6.3 Connect Power Connect a 24V power supply to the unit. See the pin out in Figure 2 for more information. 1.6.4 Check the Measurement Screen The unit should power up and display "OFF" on the measurement screen. Do not attempt to turn on the high voltage. 1.6.5 Power down the MX7M Power down the MX7M and install it on a vacuum stand for use. 2 Setup 2.1 Installation Each MX7M is designed to be used in conjunction with a 7M se ...

Figure 2: MX7M Electrical Connection Information Pin Description 1 Analog Output (Ground) 2 RS-485 A(-) 3 SP2 NC 4 SP2 NO 5 SP1 Open Drain 6 Starter Output (5V) 7 Starter Output (Ground) 8 Supply Voltage 9 Analog Output (0-10 V) 10 RS-485 B(+) 11 SP2 Com 12 SP1 Source 13 Sensor Voltage Control 14 Sensor Voltage Control 15 Supply Voltage (Ground) 2.3 Turning the High Voltage On and Off The MX7M has an operating range that does not include measurement above 1 × 10−2 Torr. If the unit is operated above 1 × 10−2 Torr, the sensor will be damaged and electrical arcing inside the sensor may occur. To prevent this, th ...

To protect the sensor from damage, if the sensor high voltage is toggled on when in either Menu Control or Pin Control mode the pressure is above 1 × 10−2 Torr, overcurrent protection will turn the sensor off. If the sensor is in Menu Control mode, then a command to turn on the sensor will need to be sent via communication or through the front panel to toggle the high voltage on again. If Pin Control is enabled, then the unit will attempt every to turn the high voltage on every 60 seconds until overcurrent protection does not occur. 2.4 Menu Navigation The MX7M contains many operator customizable features. Changi ...

(e) Analog Output Adjustment 5. Set Points (a) SP1 Off (b) SP1 On (c) SP2 Off (d) SP2 On 6. Output (a) Analog Output i. Linear A. 10 V Pressure B. 0 V Pressure (Non-settable) ii. Linear by Decade iii. Linear by Decade 7F iv. Logarithmic A. 10 V Pressure B. 0 V Pressure (b) RS-485 Output i. Address ii. Baud Rate email: [email protected] tel: +1 215 947 2500 web: frederickscompany.com mx7m_im rev C 8 of 23 ...

2.6 Explanation of Menu Items and Navigation Below is a general explanation of each level of the MX7M menu structure. 2.6.1 Measurement Screen The measurement screen contains the reading of the sensor in easy-to-read blue digits and includes units. In addition to the digital reading, the yellow bar on the measurement screen provides an analog indication of the pressure based on a logarithmic scale. At 1 × 10−2 Torr the yellow bar should stretch across the width of the screen. At 5 × 10−11 Torr the yellow bar will disappear, and at 7 × 10−7 Torr, the yellow bar will be approximately half way across the scree ...

B. Gas Type The MX7M is an indirect pressure sensor and its accuracy will be effected by the presence of gases other than nitrogen. The MX7M has the ability to apply correction factors for six pre- defined gases: hydrogen, helium, neon, argon, krypton, and carbon dioxide. These correction factors have been experimentally determined by Televac to yield the maximum accuracy avail- able. Conversion factors for use with the MX7M when gases to be measured are other than Nitrogen are listed. For users wishing to manually apply the conversion, multiply the unit read- ing by the factor in the table below to convert to the c ...

ˆ Press UP or DOWN until the unit matches the reference in use for calibration. ˆ Press ENT to save the adjustment. Press SEL to exit without saving. Note 1: Calibration should be performed in the following order: 1 × 10−6 Torr adjustment, 1 × 10−5 Torr adjustment, 1 × 10−4 Torr adjustment, 1 × 10−3 Torr adjustment. Failing to calibrate in this order will result in inaccuracies. Note 2: CHANGING CALIBRATION SETTINGS VOIDS NIST-TRACEABLE CALIBRATIONS! A. 10−6 Torr The 1 × 10−6 calibration point allows the gauge to adjust the pressure reading at 1 × 10−6 Torr. This calibration point should not be ...

ˆ Press UP and DOWN to change the value. ˆ When the desired reading is reached, press ENT to save the change or SEL to navigate away without saving the change. 2.6.6 Output The MX7M provides a user selectable analog output as well as RS-485 and USB digital outputs. To modify the output settings: ˆ Navigate to the measurement screen. ˆ Press SEL five times. ˆ Press UP and DOWN to navigate between the analog output and RS-485 screens. ˆ When the desired field is present, press ENT to enter the heading. ˆ To change the desired setting, press ENT to unlock the setting. ˆ Press UP or DOWN to adjust the setting. � ...

Votge Otpt × 10H−1 = Pressre To select the Linear output, navigate to the Analog Output screen, press ENT, and then use the UP or DOWN arrow to select Linear. Press ENT to save the change. Then press DOWN once to navigate to the Output High screen. Press ENT to unlock the screen and press UP or DOWN to select the full scale pressure for the analog output. B. Linear by Decade The Linear by Decade output spans the MX7M measurement range. It uses the units digit of the voltage reading to communicate the decade of the pressure reading and the units after the decimal to communicate the specific pressure ...

Pressre (Torr) = 10 3.075 2.5 −7 = 1.7 × 10−6 Torr To select the Logarithmic output, navigate to the Analog Output screen, press ENT, and then use the UP or DOWN arrow to select Logarithmic option. Press ENT to save the change. Press the DOWN arrow to navigate to the 10 V exponent selection screen. Press ENT to unlock and then the UP or DOWN arrow to select the value. Press ENT to save the value. Press the DOWN arrow to navigate to the 0 V exponent selection screen. Press ENT to unlock the screen and the UP or DOWN arrow to select the 0 V value. Figure 3: Graph of MX7M Sample Analog Output Functions email: s ...

2.8 Cleaning the MX7M Sensor Refer to Figure 4 while cleaning the 7M sensor. Before disassembling the sensor, ensure that the unit is removed from any power source and is removed from the vacuum system. Also ensure that you have a new copper gasket or a o-ring. See the parts listed below. The cleaning steps are as follows: 1. Remove the sensor from the electronics assembly by loosening the two set screws in the base of the electronics. A .050” Allen wrench is necessary for this step. 2. Remove the six bolts from the top of the unit. These require a 7/64 Allen wrench. 3. The MX7M ships by default with a copper gask ...

Figure 4: Cross-sectional Diagram of the 7M Sensor email: [email protected] tel: +1 215 947 2500 web: frederickscompany.com mx7m_im rev C 16 of 23 ...

3 RS-485 and USB Communications This gauge communicates with the host computer through an RS-485 or USB interface. Each commu- nication correspondence consists of a command line sent by the host computer and a response from the gauge. To communicate with the MX7M via RS-485, the user must have an RS-485 capable device to send commands to the MX7M . Each command must be preceded by a *, the address, and will be an S, R, W, RC, or WC. To communicate with the MX7M via USB, the user must have a USB capable device to send commands to the MX7M . Each command must be preceded by a * and will be an S, R, W, RC, or WC. Becau ...

3.3 RS-485 and USB Command List Table 6: RS-485 and USB General Read Commands Command Response Description R1 xx Read units, where xx is: PA = Pa TR = Torr MB = mbar R3 xx Read resolution, where xx is: LO = low HI = high R5 xyzzabb Read analog output range, where: x = 1 (linear), 2 (log), 3 (linear-by-decade), 4 (linear-by-decade 7F) y = high value exponent sign zz = high value exponent a = low value exponent sign bb = low value exponent R6 xx Read gas type, where xx is: N2 = Nitrogen AR = Argon H2 = Hydrogen HE = Helium NE = Neon KR = Krypton C2 = Carbon Dioxide R7Y ppseePPSEE Read SPL (ppsee) and SP2H (PPSEE) sett ...

Table 7: RS-485 and USB General Write Commands Command Response Description W1xx xx Set units, where xx is: PA = Pa TR = Torr MB = mbar W3 xx Toggle resolution, where xx is: LO = low HI = high W51yzz 1yzz Set analog output format to linear, yzz = high value y = high value exponent sign zz = high value exponent W52yzzabb 2yzzabb Set analog output format to logarithmic yzz = high value, abb = low value y = high value exponent sign zz = high value exponent a = low value exponent sign bb = low value exponent W53 3 Set analog output format to linear-by-decade W6xx xx Set gas type, where xx is: N2 = Nitrogen AR = Argon H2 ...