| Input |
Through separate preamplifier (headstage) for direct intracellular
or extracellular potential recording. |
| Input socket |
8-pin Binder or Amphenol-Tuchel socket with screw lock. |
| Input capacity compensation |
Continuously adjustable between 0 and 8 pF. |
| Signal output |
Filtered output signal ±10 Volt corresponding to ±1
Volt input signal (gain 10x)
Internally on PLUGSYS system bus, assigned via a jumper to one of the signal
lines AV-1 to AV-16.
Externally by BNC socket on the front panel. |
| Amplifier bandwidth |
DC to 30 kHz (-3dB). |
| Output filter |
Low-pass in 7 steps covering 30 Hz to 30 kHz (-3dB). |
| Gain |
10x (fixed). |
| Zero balance |
Compensation of input offset in the range ±400 mV. |
| Buzzer |
AC feed through microelectrode to assist piercing the cell
membrane during microelectrode insertion. The buzz frequency is adjustable
with a 16-position switch between 10 Hz and 10 kHz to suit actual equirements. |
| Calibration signal |
Generator for signal adjustment to a computing amplifier or
recorder. Pressing the CAL key injects a complex calibration signal consisting
of the values 0 Volt, -100 mV and ±50 mV referred to the input. |
| Analogue indication |
LED bargraph with 30 LEDs for visual monitoring of applied
signal (7.5 mV per LED referred to input). For accurate zeroing the bargraph
range can be expanded by a key (magnifier function) to 1.5 mV per LED referred
to input. |
| Audio monitor |
Audible monitoring system for measurement signal using a monitoring
tone whose frequency is modulated according to signal amplitude. Loudness
and base frequency are individually adjustable by trimmer on the front panel. |
| Microelectrode function test |
Check of microelectrode by feeding in (via the headstage)
a constant current for approximate measurement of instantaneous electrode
resistance. Since the measurement current may damage the microelectrode
by electrolysis the test duration is automatically limited to 2 seconds. |
| Supply |
5 V 1.2 A from PLUGSYS system bus. |
| Dimensions |
19" PLUGSYS module, width 12 E (60.96 mm), height 3 U
(128.7 mm). |
| Weight |
400 g. |
| Construction |
Screened metal case with microelectrode holder integral with
mounting rod, 2 mm socket for bath reference and screen connection for central
ground. The headstage is independent of the MEA amplifier used and does
not require adjusting to it. |
| Mounting |
By 8 mm dia. support rod and integral microelectrode holder
suitable for mountings of conventional micromanipulators as replacement
against the standard microelectrode holder. |
| Microelectrode resistance |
Suitable for microelectrodes in the range 1 to 100 MOhm. |
| Input circuit |
Fully integrated electrometer amplifier with driven screen,
boot-strapped supply and capacity compensation. |
| Input current |
compensated to zero. |
| Coupling resistor |
1 GOhm. |
| Capacity compensation |
Adjustable over 0 – 8 pF |
| Frequency range |
DC to 75 kHz (-3dB) |
| Supply |
From MEA microelectrode amplifier Type 695. |
| Connecting cable |
Signal and supply cable 1.95 m long with 8-pin Binder or Amphenol-Tuchel
plug to suit MEA microelectrode amplifier. |
| Dimensions |
Length 140 mm, width 22 mm, height 22 mm. |
| Weight |
160 g. |
