Inside the Mark Super VII

The Hubbard Professional Mark Super VII is the most sophisticated and expensive e-meter yet developed by the Church of Scientology. Its retail price in 1995 was US $3,850. It is the standard e-meter in use today. Although the earlier Mark V model is still offered for sale, for auditing on the OT levels the Mark Super VII is required .

Hubbard Professional Mark Super VII placard

Although the Church of Scientology claims that their e-meters are made of special high-precision components, the electronic technology in the Mark Super VII is ordinary 1980s-era VLSI, including an Intel 8051 8-bit microprocessor. An electrical engineer who examined the meter in November, 1995 estimated that devices of this type, custom-manufactured and sold in low volume, would normally retail for around $300 today. That is one twelfth the Church's asking price.

Controls and Indicators

The Cans: electrodes used to measure skin resistance. Normally one is held in each hand. (For solo auditing, both are held in one hand.) Because the quality of the electrical contact depends on one's grip on the electrodes, there is ample opportunity for tiny, unconscious muscle movements in the fingers to influence the readings.
Tone Arm Knob: the primary range control. At a TA setting of 2, the needle will be at the setpoint when the resistance across the cans is 5,000 ohms. At a TA setting of 3, the needle will be at setpoint at 12,500 ohms. The meter comes with a pair of reference resistors so that its calibration can be checked at these two values. At the start of an auditing session the TA should be between 2 and 3.
Trim Knob: the secondary range control. Used to fine-tune the range setting by adjusting the needle slightly to get it to the setpoint. (The digital display of TA value does not change when the trim knob is moved.)
Sensitivity Knob: fine tunes the gain on the amplifier to control the amount of resistance change necessary to obtain a full scale needle deflection. With too low a sensitivity setting, the needle will just sit at the setpoint. With too high a setting, every little twitch sends the needle offscale. A normal sensitivity value is around 5.
Sensitivity Booster Switch: coarse control of amplifier gain. Values are Low [16], Normal [32], and High [64].
Mode Switch: values are Off, On, and Test. In Test mode the needle should swing rightward and indicate in the ``Test'' region of the scale. If it fails to reach this region, the batteries are low. The needle should bang smartly off and then settle against the righthand pin when the E-Meter is charged.
Needle: analog needle displaying current flow across the cans: the inverse of resistance. A leftward movement of the needle is called a ``rise'' (increased resistance); a rightward movement a ``fall''.
Clock: a digital clock/calendar. This is a separate circuit board, mounted underneath the main board.
TA Counter: Cumulative measure of ``downward'' TA motion (counter-clockwise movement of the knob), displayed digitally. For example, suppose the auditor moves the TA setting from 2.5 to 2.2. The TA Counter will increase by 0.3. Only decreases in TA are counted; increases in the TA setting are ignored by the counter. The total downward TA motion during an auditing session is recorded on the auditor's worksheet; it is supposed to signify ``release of charge.''
TA Setting: digital display of current tone arm setting.
Meter Check Button: A pushbutton that temporarily disconnects the electrodes from the meter. A tiny amber LED located just above the button lights up when the electrodes are disconnected. This arrangement allows the auditor to quickly check the meter's calibration, or to check for a malfunction if the PC is rockslamming. (The rockslam indication could be caused by a meter fault, or by the PC touching the cans together. If the meter checks out okay then the PC really is rockslamming and the auditor must deal with it.) Pushing the button again reconnects the electrodes and extinguishes the LED.

Data Plate

Click for full-scale image
This data plate is affixed to the bottom of the meter. The serial number and dates have been masked in the image to prevent the Church's security division (the Office of Special Affairs) from tracing the unit. The text on the left side of the data plate is a disclaimer that was required by the US FDA (Food & Drug Administration) after Hubbard's medical claims grew too outrageous.

On January 4, 1963, however, the Food and Drug Administration raided the Washington Church... The FDA seized a huge quantity of E-meters and books. As with "Dianazene," the FDA charged mislabelling... Eventually, the FDA won their case against the labelling of the E-Meter, and forced the Scientologists to label it ineffective in the diagnosis or treatment of disease. The Scientologists failed to thoroughly comply with the ordered wording...
Jon Atack, A Piece of Blue Sky, p. 154

Here is the actual wording on the Super Mark VII's data plate:

HUBBARD ELECTROMETER MANUFACTURING
By itself, this meter does nothing. It is solely for the guide of Ministers of the Church in Confessionals and pastoral counselling. The Electrometer is not medically or scientifically capable of improving the health or bodily function of anyone and is for religious use by students and Ministers of the Church of Scientology only. HUBBARD, E-METER and SCIENTOLOGY are trademarks and service marks owned by RTC and used with its permission.

Main Assembly

Click for full-scale image
This is the main assembly of the Mark Super VII. The black donut-shaped objects surrounding some wires on the main board are inductors that suppress electronic interference between the analog and digital sides of the device. The blue rectangular boxes arranged in a row are ``trim pots,'' or variable resistors (potentiometers).

An internal serial number plate has been masked in the image to prevent the Office of Special Affairs from tracing the unit.

Main circuit board
Here is a closer view of the main circuit board. It contains an Intel 8051 microprocessor, an LCD display driver chip for the TA Setting and TA Counter displays, and various other components.

Close-up shot of the Intel 8051 microprocessor

Why Is There a Microprocessor?

The Mark Super VII would seem to be over-engineered. However, it is capable of more than just measuring resistance across the cans. It can be connected via a jack on the back to a ``master'' meter, so that a course supervisor can monitor the actions of the auditor from another room. The unit must therefore be capable of transmitting the current TA setting, TA counter, and needle position to the master unit several times per second. Digital technology is an appropriate solution in this case.

The Super Mark VII also accepts a ``remote tone arm:'' a little box with its own tone arm knob that is placed to the right of the e-meter. The box has a cable that plugs into another one of the jacks in the back of the meter. Remote tone arms are for solo auditors, who will want to both work the knob and take notes with their right hand while holding the cans in their left hand. This is awkward to do using the meter's built-in tone arm knob, since it is on the far left side of the unit.

Back side of the e-meter
This view of the outside back of the e-meter shows the four jacks. Two are for the charger (allowing for two different plug styles), one is for the remote tone arm, and one for connection to a course supervisor's ``master'' meter. When the charger is plugged in, a red LED lights up to indicate that the charging circuit is active.

Also visible in the picture are two rectangular rubber feet, and two of the three rubber grommets located on the back of the meter. Pulling these grommets out uncovers the screws that must be removed to open the meter.

Below is a picture of the inside of the back half of the unit, showing the connections from the jacks to the main and charger circuit boards.

Inside view of back of e-meter

Batteries and Charging Circuit

Battery board holds seven batteries (three on top side.)

See this important note about battery leakage.

The e-meter uses rechargeable Panasonic NiCad batteries. It comes with a plug-in charger that converts house current to 12 volts/300 milliamps AC. The charger plugs into a jack in the back of the unit, which connects to the charging circuit board:

Charging circuit

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