Flash Illuminance & Luminous Color Photometer
P-9801-1 Optometer
CT-4501-1 Illuminance & RGB Color Detector

The P-9801 optometer is one of the most powerful multi-channel light measurement instruments available. It can be used with up to eight light detector heads and features:

• simultaneous measurement of all eight detector channels
• wide linear detector signal dynamic range
• short rise time with variable sampling rate
• fast multi-channel data-logging
• manual and remote control operation
• powerful 16 bit microprocessor with large memory
• external trigger input with pre-trigger function

Due to its ability to simultaneously measure of all signal channels the P-9801 is ideal for the measurement of short duration events such as light flashes. Combined with the CT-4501-1 detector the P-9801 becomes an illuminance and luminous color meter for light sources operated in steady-state or flash mode. The P-9801 with CT-4501-1 is recommended for:

• universal laboratory light measurement instrument for illuminance and luminous color
• effective luminous intensity measurement of anti-collision lighting, mobile phone flashing light, warning signals and beacons
• luminous intensity distribution measurement of anti-collision lighting, mobile phone flashing light, warning signals when mated with a goniometer bench

The P-9801 offers two different measurement modes for light flashes:

• pulse energy measurement mode where the energy of the light flash is integrated. Measurement values are displayed in (lxs) lux-seconds, xy chromaticity values and color temperature. Integration is done by a pulse stretching method enabling the measurement of light flashes with pulse lengths shorter than the meter rise time.
• pulse shape is measured with high speed data logger. Pulse length, peak intensity, integral of the pulse energy and color values are calculated using the logged data. The P-9801 offers unique features for short event measurement like an internal trigger selectable for the measurement signal of channels 1 to 8 or external trigger. The pre-trigger function enables the measurement of the signal before the triggered event. Here the sampling rate of the data logger measurement is limited by the rise time of the optometer.

Three different versions of the P-9801 are available:

1. P-9801-V01 with gain dependent rise time for use as lab based universal light meter
2. P-9801-V02 with 20ms gain independent fixed rise time for pulse energy measurement of very short light events
3. P-9801-V03 with 1ms gain independent fixed rise time for fast data logging measurement of short light events

Calibration of the CT-4501-1 detector’s photometric and luminous color sensitivity includes the relative spectral sensitivity of all four filtered photodiodes for uncertainty check and correction for monochromatic sources including line spectrum light sources or LEDs.