Other Equipment :
        We use flashlights to see and walkie-talkies to communicate in the dark.  Laptop PC's are used for various things, but mainly to record the wireless audio.  Wireless audio is basically a cordless microphone placed in another room and then monitored live on the laptop for strange sounds or voices.
We use scientific equipment to document and record paranormal activity.  After the investigation we review the evidence we recorded.  Then we analyze anything that is odd.  Most things can be explained so those bits of evidence are dismissed.  Here is some of the equipment we use during an investigation.  Click on the pictures to enlarge.
Digital Voice Recorder :
        
Captures EVP's.  EVP stands for Electronic Voice Phenomena.  These are disembodied voices that are recorded at the time of the investigation but no one hears it until the recorder is reviewed. 
Digital Camera or 35mm Camera :
        Use this to take still pictures to possibly capture an image of an apparition, orb, mist, etc.
Camcorder with nightvision :
        
They provide constant visual and audio observation of the investigation for review.  It has the capability to record in total darkness by using Infrared lights.
IR Lamp or IR Light :
        IR stands for Infrared.  Infrared is part of the light spectrum our eyes cannot see.  However, technology has developed to allow IR lamps and lights to be recorded on film. So upon reviewing the recording, we can see what was going on in the dark.  IR Lamps are a collection of IR LED bulbs on one device.  They are basically mini IR spotlights.  These lamps help "light" up the room and allow the camcorders to record better.  IR Lights are the infrared rays emanating from the IR LED bulbs.
EMF Detector and K II Meter:
        EMF stands for Electromagnetic Field.  EMF is defined as the field of force associated with electric charge in motion, having both electric and magnetic components and containing a definite amount of electromagnetic energy.  We use the EMF detector to find this electromagnetic energy.  Electrical devices have a field.  Wires, PC's, stoves, lights, outlets, etc., are some examples.  However if the detector reads a spike in the field and we cannot trace it to any electrical device it may be an indication of the presence of an entity.  A change in the field's intensity may also indicate this. K II's are designed to be more sensitive for possible interaction with an entity.